Penalty for non filing of returns

Last Date for Financial Year 2011-12 is 31st March 2013

You can file return u/s 139(1) upto 31st July

but you can file your this year return u/s 139(4) for next 2 years last day will for  filing of your return will be 31st 2015

Financial year 2012-13 is the assessment year 2013-14 which come s to file the returns from 1st April 2013 nd 31st july 2013..and there after interest will be charged U/s 234 A.  It can b filed even after 31st Macrh 2014 and uo to 31st March 2015 but penalty can be imposed by assessing officer if the reason for delay filing is not satisfactory..

I agree withM.R.K. Parsad.

But whereas your question all the relevent information is been provided