Last year itr filed for wrong year

Dear All,

i don't know how i did this mistake but when i filed ITR last year i filed for year 2011 to 2012, which was supposed to be for 2012 to 2013. I even signed and submitted it last year. Somehow i was going through my document yesterday and found this mistake.

Now there are two ITR's for year 2011 to 2012, the correct one and the wrong one. Please advise what can be done.

Thanks in advance.

Regards,

Muzamil