A margin penalty is levied in below scenarios:
Change in margin requirement from the exchange end
Change in requirements
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.