Margin requirements bull call spread at expiry

Assuming a stock’s spot is at 2100 and if i buy 2050 call and sell 2150 call 1 lot each. Margin would be something like under 1 lakh.

Now 2 days before expiry if the spot is 2120 then would I need to bring in more margin to hold the ITM call even if I plan to sell it just before expiry day i.e. I don’t want delivery of stock but cash settled.

Yes, if your Long Option position is ITM, you’ll need additional margin and the exchange blocks physical delivery margin from expiry minus 4 days. You can refer to this support article for more information.

Usually is the margin on expiry minus 4 days is double the normal dates for long ITM options?

Is there any calculator for margin calculation for expiry minus 4 days?

The margin increases in phases.

There’s no calculator, but here’s how the calculation works: