Is it mandatory for option buyer also need extra margin as per sibi rule?

How much margin required for this scenario :

Buy 2 lots of bank nifty (otm) option strike price 36000. @ 62
spot price 35710
after some time bank nifty spot traded at 36220
now (otm) option become (itm) @ 230
on expiry day.
this trade cost 62 x 50 = 3100 only. is enough margin or we need more because otm converts into itm.
what happens if we close before market close or we didn’t?

Index Options are cash settled, even if your position is ITM, you won’t need any additional margins to hold your position.

The requirement for additional margin for ITM Options during expiry week is applicable for Stock F&O, as these are physically settled. Explained here.

thank for you reply
what then extra stt will apply.
is it applicable for seller also?

The STT is not applicable on seller as STT is already paid when one takes Short position.