For intraday (selling and buying within the same day between 9 am to 3.30pm) it is possible to short sell amd then buy back stocks. Short selling is also called 'sell against margin' or 'SAM'
If you want to keep trades open for a few days then go for FNO.
FOR INTRADAY First place a sell order, after it is executed place a buy order - or better go to your 'net position' of sold stocks and select the option to 'square off' to make sure that those same stocks are bought back, and a fresh order to buy new stocks is not placed. These are common terminology and might be the same as used by your brokerage software. I use sharekhan by the way.