I tried implementing the same but was not successful.

Here is the full code. I need to auto-fill H and I columns. All other columns are fully populated. 

    Range("H2").Select
    Application.CutCopyMode = False
    Selection.AutoFill Destination:=Range("H2:H139274")
    Range("H2:H139274").Select
    Range("I2").Select
    ActiveCell.FormulaR1C1 = "=VLOOKUP(RC[-6],Blacklist!C[-8],1,FALSE)"
    Range("I2").Select
    Selection.AutoFill Destination:=Range("I2:I139274")
    Range("I2:I139274").Select
    Range("I1").Select
    Selection.AutoFilter
End Sub