If you buy on a trading day (T) the exchange will conduct an auction market from 2 pm to 2:30 pm on T+1 day to collect the short quantities from other sellers to deliver the stocks to the buyers. The auction price will be determined as per the T-dayT day closing price. 

The exchange delivers the stock to the buyer’s at the auction price on T+2 day, The defaulting seller is obligated to pay an auction penalty and difference amount to the exchange.