Section 139(1) and 139(2)

First you should check whether rotation of auditors is applicable to you u/s 139(2).  If yes, term should  be as specified in the Rules.  If  not, appointment should be upto 6th AGM u/s 139(1).

Dear Ajay,

If your company does not fall under prescribed companies to  retire auditor by rotation, your company can appoint existing auditor for period of five year in ensuing annual general meeting even though auditor has already completed 5 year, since retire by rotation is not applicable for your company.