Is there any provision to file a revised return?

Yes, under rule 7B of Service Tax Rules, 1994 an assessee may submit a revised return, in Form ST-3, in triplicate, to correct a mistake or omission, within a period of ninety days from the date of submission of the return under rule 7. However, where an assessee submits a revised return, the ‘relevant date’ for the purpose of recovery of service tax, if any, under section 73 of the Act shall be the date of submission of such revised return.