Return filing late

yes

Belated Return (Sec. 139 (4))

If the return is not filed within the time allowed under section 139(1), the person may before the assessment is made, furnish the return of any previous year at any time before the end of one year form the end of relevant assessment year.

In your case (i.e. P.Y.  2010-2011) Asst. Year 2011-2012

One year form the end of relevant assessment year, end on 31.03.2013.

Therefore, he can file return upto 31.03.2013.

However :

He will be liable for interest u/s 234A

A penalty of Rs. 5000/- may be imposed u/s 271F.