ITM positions at Expiry for Nifty or Bank Nifty


What happens to short positions (CE SELL or PE SELL) which expires in the money (ITM), for Nifty or Bank Nifty, if the same are not squared off?
Kindly elaborate in terms of STT, Premium Collected etc

STT for options is only on the sell-side which means you would’ve paid STT when initiating the short. So, there will be no STT impact on expiry.

The losses will be made good from cash, failing which, there will be a debit balance.