auditor

Aa retiring auditor can be re-appointed at an Annual General Meeting if:

The auditor is not disqualified for re-appointment.

The auditor has not given the company a notice in writing of his unwillingness to be re-appointed.

A special resolution has not been passed at that meeting appointing some other auditor or providing expressly that he shall not be re-appointed.

If at any Annual General Meeting, no auditor is appointed or re-appointed, the existing auditor will continue to be the auditor of the company.

he should continue even on completion of his tenure of 5 /10 years as the case may be is it ?

no he can not

if disqualification attract in this case

After completion of his or its continuous term of 5/10years as the case may be ,the matter shall go to AGM for deciding about his continuance.