Can i fill my previous year ITR

CHANDAN JANGID (Lead A & F) (61 Points)

15 December 2012  

Dear Sir,

I have not deposited any ITR in previous year coz my income was not Taxable. But now I filling my previous two year ITR i.e. F.Y. 2010-2011 and 2011-2012. Please tell me can i filling my Previous NIL Returns. I am salaried person but my salary is not taxable. Please tell me urgent which amount of penalty shall be applicable.