Rectification notice

I filed the return U/S 192 i.e. a salary return within the due date as per section139(1) for th financial year 2012-2013(A.Y 2013-14). But I have got a notice under section 154 for Rectification of mistake apparent from record and I need to respond within 15 days from receipt of notice. 

                                                                   My question is that can I file a Revised Return and correct that mistake. But what about the requirement of responding within the stipulated time. Plzzzzzzzzz help.