If a person having funished return under section 139(1) or in pursuance of a notice u/s 142(1)(i)
he may furnish a revise return at any time :
-
before the expiry of one year from the end of the relevant AY
-
before the completion of Assessment
.............. whichever is earlier
Please Note : Assessment here refers to assement u/s 143(3) & 144 but not under 143(1) therefore a return can be revised after an intimation u/s 143(1) has been served since intimation u/s 143(1) is not an assessment CIT V S.R Koshti (2005)HC
In your case your PY is 2008-09
you filed the return under section 139(1) before due date i.e 31/07/09
last date of filing your Revised return is 31/3/11 and u can still file a revise return if assement order under section 143(3) & 144 have not been passed by AO
hope it will give you some clarity :)
thanks