Comment on Consequences of Short delivery - NSE/BSE
Confused if you are talking as the buyer who didn’t get the shares or as the seller who defaulted.
If you are the buyer, you get the shares, instead of T+2 on T+3 days.
If you are the seller who defaulted, exchange will try to buy the shares on auction, and the upper limit is 20% above the closing price of that stock on the T+3 day. Check this link.