Sure, I can help you with that. Here's a VBA code snippet that you can use to rename multiple files in multiple folders within a parent directory in Excel:

Sub RenameFiles()
    Dim parentPath As String
    Dim oldName As String
    Dim newName As String
    Dim folderPath As String
    Dim fileName As String
    Dim folder As Object
    Dim subFolder As Object
    Dim file As Object

    'Get parent directory path from user
    parentPath = InputBox("Enter the path of the parent directory:")

    'Get the name to replace from cell E10
    oldName = Range("E10").Value

    'Get the new character to add from cell F10
    newName = Range("F10").Value

    'Check if the parent directory exists
    If Dir(parentPath, vbDirectory) <> "" Then
        'Loop through all subfolders in the parent directory
        For Each folder In CreateObject("Scripting.FileSystemObject").GetFolder(parentPath).subfolders
            folderPath = folder.Path

            'Loop through all files in each subfolder
            For Each file In CreateObject("Scripting.FileSystemObject").GetFolder(folderPath).Files
                fileName = file.Name

                'Rename the file if the old name is found
                If InStr(fileName, oldName) > 0 Then
                    'Replace the old name with the new character
                    fileName = Replace(fileName, oldName, newName)
                    file.Name = fileName
                End If
            Next file

            'Loop through all subfolders within subfolders
            For Each subFolder In CreateObject("Scripting.FileSystemObject").GetFolder(folderPath).subfolders
                For Each file In CreateObject("Scripting.FileSystemObject").GetFolder(subFolder.Path).Files
                    'Rename the file if the old name is found
                    If InStr(file.Name, oldName) > 0 Then
                        'Replace the old name with the new character
                        file.Name = Replace(file.Name, oldName, newName)
                    End If
                Next file
            Next subFolder
        Next folder

        MsgBox "Files renamed successfully!"
    Else
        MsgBox "Parent directory not found!"
    End If
End Sub

In this code, you will be prompted to enter the path of the parent directory when you run the macro. The old to be replaced should be in cell E10, and the new character to be added should be in cell F10. The code will recursively go through the subfolders within the parent directory and rename any files that contain the old name with the new character.

Please note that it's essential to double-check the path and be cautious when renaming files. Make sure to test the code on a backup of your files before running it on actual data.

Sure, here is your revised VBA code with the prompts for entering the text to be replaced and the replacement text:

Sub sagar()
    Dim ParentFolder As String
    Dim FileExt As String
    Dim FolderPath As String
    Dim Folder As Object
    Dim File As Object
    Dim NewFileName As String
    Dim strReplace As String
    Dim strWith As String

    ' Prompt for the parent directory path
    ParentFolder = InputBox("Enter the parent directory path:")

    ' Prompt for the file extension
    FileExt = InputBox("Enter the file extension (e.g., .txt):")

    ' Prompt for the text to be replaced
    strReplace = InputBox("Enter the text to be replaced in file name:")
    
    ' Prompt for the new text to replace the old text
    strWith = InputBox("Enter the new text to replace the old text:")    

    ' Check if the parent directory exists
    If Dir(ParentFolder, vbDirectory) = "" Then
        MsgBox "The specified parent directory does not exist."
        Exit Sub
    End If
    ' Loop through all subfolders in the parent directory
    FolderPath = Dir(ParentFolder & "*", vbDirectory)
    Do While FolderPath <> ""
        If FolderPath <> "." And FolderPath <> ".." Then
            ' Iterate through files in the current folder
            Set Folder = CreateObject("Scripting.FileSystemObject").GetFolder(ParentFolder & FolderPath)
            For Each File In Folder.Files
                If Right(File.Name, Len(FileExt)) = FileExt Then
                    ' Replace strReplace with strWith in the file name
                    NewFileName = Replace(File.Name, strReplace, strWith)
                    ' Rename the file
                    Name ParentFolder & FolderPath & "\" & File.Name As ParentFolder & FolderPath & "\" & NewFileName
                End If
            Next File
        End If
        FolderPath = Dir ' Get the next folder
    Loop
End Sub

In this code, you will be prompted to enter the parent directory path, file extension, text to be replaced, and replacement text when you run the macro.

Sure, here is your updated VBA code where user will be asked to provide three file extensions, as well as texts to replace and what to replace with. If the user provides fewer than three types, the macro will still run for the provided types:

Sub sagar()
    Dim ParentFolder As String
    Dim FileExt(1 To 3) As String
    FolderPath As String
    Dim Folder As Object
    Dim File As Object
    Dim NewFileName As String
    Dim strReplace As String
    Dim strWith As String
    Dim i As Integer

    ' Prompt for the parent directory path
    ParentFolder = InputBox("Enter the parent directory path:")

    ' Prompt for the file extensions
    For i = 1 To 3
        FileExt(i) = InputBox("Enter the file extension " & i & " (e.g., .txt). Leave blank if not applicable:")
    Next i

    ' Prompt for the text to be replaced
    strReplace = InputBox("Enter the text to be replaced in file name:")
    
    ' Prompt for the new text to the old text
    strWith = InputBox("Enter the new text to replace the old text:")    

    ' Check if the parent directory exists
    If Dir(ParentFolder, vbDirectory) = "" Then
        MsgBox "The specified parent directory does not exist."
        Exit Sub
    End If

    ' Loop through all subfolders in the parent directory
    FolderPath = Dir(ParentFolder & "*", vbDirectory)
    Do While FolderPath <> ""
        If FolderPath <> "." And FolderPath <> ".." Then
            ' Iterate through in the current folder
            Set Folder = CreateObject("Scripting.FileSystemObject").GetFolder(ParentFolder & FolderPath)
            For Each File In Folder.Files
                For i = 1 To 3
                    IfExt(i) <> "" And Right(File.Name, Len(FileExt(i))) = FileExt(i) Then
                        ' Replace strReplace with strWith in the file name
                        NewFileName = Replace(File.Name, strReplace, strWith)
                        ' Rename the file
                        Name ParentFolder & FolderPath & "\" & File.Name As ParentFolder & FolderPath & "\" & NewFileName
                    End If
                Next i
            Next File
        End If
        FolderPath = Dir ' Get the next folder
    Loop
End Sub

In this code snippet, an array is used to store three file extensions (FileExt(1 To 3)). It loops over each file extension and checks each against the file names. Only if the resulting extensions and the user-provided extensions match are the files renamed.

Apologies for the confusion. I believe I misunderstood your original request. Here's a VBA code:

Sub sagar()
    Dim ParentFolder As String
    Dim FileExt(1 To 3) As String
    Dim FolderPath As String
    Dim Folder As Object
    Dim File As Object
    Dim NewFileName As String
    Dim strReplace As String
    Dim strWith As String    Dim i As Integer

    ' Prompt for the directory path
    ParentFolder = InputBox("Enter the parent directory path:")

    ' Prompt for the file extensions
    For i = 1 To 3
        FileExt(i) = InputBox("Enter the file extension " & i & " (e.g., .txt). Leave blank if not applicable:")
    Next i

    ' Prompt for the text to be replaced
    strReplace = InputBox("Enter the text to be replaced in file name:")
    
    ' Prompt for the new text to replace the old text
    strWith = InputBox("Enter the new text to replace the old text:")    

    ' Check if the parent directory exists
    If Dir(ParentFolder, vbDirectory) = "" Then
        MsgBox "The specified parent directory does not exist."
        Exit Sub
    End If

    ' Loop through all folders in the parent directory
    FolderPath = Dir(ParentFolder & "*", vbDirectory)
    Do While FolderPath <> ""
        If FolderPath <> "." And FolderPath <> ".." Then
            ' Iterate through files in the current folder
            Set Folder = CreateObject("Scripting.FileSystemObject").GetFolder(ParentFolder & FolderPath)
            For Each File In Folder.Files
                For i = 1 To 3
                    If FileExt(i) <> "" And Right(File.Name, Len(FileExt(i))) = FileExt(i) Then
                        ' Replace strReplace with strWith in the file name
                        NewFileName = Replace(File.Name, strReplace, strWith)
                        ' Rename the file
                        Name ParentFolder & FolderPath & "\" & File.Name As ParentFolder & FolderPath & "\" & NewFileName
                    End If
                Next i
            Next File
        End If
        FolderPath = Dir
    Loop
End Sub

In this updated code, it separately checks each file against all three given extensions. If a file matches any of the given extensions, the renaming operation is applied.

To implement this, you would need to use a UserForm so that you can select multiple items from a list box at once. Here is a simplified example of how you could implement this:

Step 1: From the VBA Editor, click on Insert > UserForm to create a new UserForm.

Step 2: In the toolbox, click on ListBox (it may look like a squared dotted grid), and then click/drag on the UserForm to place the ListBox.

Step 3: Set the MultiSelect property of the ListBox to 1 - fmMultiSelectMulti

Step 4: Double-click on the UserForm and put the following code in the code module of the UserForm:

Private Sub UserForm_Initialize()
    With Me.ListBox1
        .AddItem ".indd"
        .AddItem ".idml"
        .AddItem ".jpg"
        .AddItem ".pdf"
    End With
End Sub

Step 5: Add a Button to UserForm and to get selected items from ListBox when button clicked use following code:

Private Sub CommandButton1_Click()
    Dim i As Integer
    Dim FileExtensions As String
    
    For i = 0 To Me.ListBox1.ListCount - 1
        If Me.ListBox1.Selected(i) Then
            FileExtensions = FileExtensions & Me.ListBox1.List(i) & ","
        End If
    Next i

    Hide
End Sub

Step 6: Then you could use the UserForm from your sagar subroutine:

Sub Sagar()
    Dim UserForm1 As New UserForm1
    UserForm1.Show

    Dim FileExt() As String
    FileExt = Split(UserForm1.Output, ",")
    ' the rest of your code...
    
    '... and change the loop that checks the file extensions to something like this:
    For Each Ext In FileExt
        If Right(File.Name, Len(Ext)) = Ext Then
            ' Perform the replacement operation
        End If
    Next Ext
End Sub

Please note, you must replace UserForm1 and ListBox1 the name of your UserForm and ListBox. This is a simplified example and you might need to adjust it to fit it into your code. Also, if you want to prevent the usage of the Excel spreadsheet while the form is showing, you should change UserForm1.Show to UserForm1.Show vbModal.