Income tax refund if return not file

yes you can claim the refund.

return can be filed within one eyar from the end of the A.Y. in whihc the return was required to be filed.

FOR F.Y 2010-11

DUE DATE - FOR AUDIT ASSESSEE - 30 SEP, NON AUDIT - 31 JULY

RETURN FILED UPTO 31-03-12  NO PENALTY, ONLY INTEREST ON TAX AMOUNT

RETURN FILED UPTO 31-03-13  IF THERE IS A TAX IN RETURN - PENALTY OF RS 5000 + INTEREST ON TAX

AFTER 31-03-13 NOT POSSIBLE TO FILE RETURN IN ANY MANNER

File the return in reply to the notice received by you. that noticed must be u/s 142(1). File the return and claim the refund