Revise service tax return

One of our client did not deposited service tax on a invoice of Advocate in Reverse charge mecanism for the month of feb 2014 now this fault is become known during audit.

Know my query is this if we deposit service tax know than can we revise our service tax return filed in april 2014 since 90 days already lapsed. if we can not revise than what is remedy  

Thanks & Regards,

Jitender