Journal entry on deferred tax at what stage

Kindly advise on journal entries:-

1. Deferred tax entry in our books of accounts at what stage.

2.  As per accounts at Mar end,Rs.1 L is tax payable. After tax audit, tax amt is revised to Rs.2 .50 L. Should we reverse Rs.1L in Oct and make full provision of Rs.2.5L and pay tax for previous year. Then how it impacts last years profit?

Regards