A margin penalty is levied in below scenarios:
Change in margin requirement from the exchange end
Change in requirements
t based on your trading (example, exiting one of multiple hedge positions)
For long Options positions (ITM), Margin requirement increases as it nears expiry date.
Note: In case you incur a margin penalty, the cut-off/ due date for reporting margin is T+5 days, so we post the entry on your ledger once we get the penalty file from the exchange i.e on T+6 day. There may be a provisional block in your account during this time period.