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.
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