Hi Rajesh,

Please don't post question on Tips & Tricks forum. That forum meant to be provide cool tips and tricks only.
If you have a specific question please post the question on the main forum.

Paste the following code in ThisWorkbook module of your workbook.

Code:
Private Sub Workbook_Open()
    
    Dim wksTarget       As Worksheet
    Dim rngDate         As Range
    Dim rngData         As Range
    Dim c               As Long
    Dim LastRow         As Long
    Dim LastCol         As Long
    
    Const RangeToLock   As String = "C:AG" '<<  adjust to suit
    Const Pwd           As String = "pwd"
    
    Set wksTarget = ThisWorkbook.Worksheets("Sheet1") '<<  adjust to suit
    
    If Not blnUnlockedAllCells Then
        wksTarget.Cells.Locked = False
        blnUnlockedAllCells = True
        wksTarget.Protect Password:=Pwd, userinterfaceonly:=True
    End If
    
    With wksTarget
        LastRow = .Range("a" & .Rows.Count).End(xlUp).Row
        LastCol = .Cells(2, .Columns.Count).End(xlToLeft).Column
        Set rngData = wksTarget.Range("a2", .Cells(LastRow, LastCol))
    End With
    
    For c = 3 To rngData.Columns.Count
        If CDate(rngData(1, c)) <= Date - 2 Then
            On Error Resume Next
            rngData.Columns(c).SpecialCells(2).Locked = True
            On Error GoTo 0
        End If
    Next
    
End Sub
adjust the sheet name and the range.