You’ve got 2 things mixed up here. Short-selling and selling in CNC are 2 different things. Short selling is when you sell first and buy back after. Selling in CNC is for the holdings present in your account. You will be allowed to sell in CNC anytime after buying the stock. After buying the stock, selling in CNC on buy day itself will be an intraday trade, selling in CNC on T1 day will be a BTST trade and after that will be a regular holding sell trade.