Revised Return after Refund is Received ?

Return for AY.2020-21 was filed in Time before Due Date(14/12/2020)

Immediately Assessment Order is passed and even Refund is Received.

Now want to file the REVISED RETURN as we forgot the Deduction of 80 c for Rs.1,50,000/-

Can we file the REVISED RETURN ?

Please advise, Thanks .