16 December 2014
Section 139(5) provides that the Income Tax return can be revised BEFORE completion of assessment. Since processing of return u/s 143(1) does NOT amount to assessment you can revise the return.
You do not need to reply to the intimation if you revise the return. If you file a revised return, it will replace the original return. The revised return will also be processed u/s 143(1).