Belated return

Sir, i am college teacher and i have received form 16 from my employer but i have forgotten to inform about ppf of rs 40000 as a result deduction u/s80c was not claimed by me and my tax liability is 12000 which was already paid. I have not filled tax return till now. So my question is that can i claim deduction of ppf in belated return( but ppf amount 40000 is not mention in form 16).if yes then am i able to claim refund.. There is no item in 80c other than ppf