Sell holding and buy back on same day at lower price

After selling the holding, again trying to buy, but margin is being asked for,why?requested to kindly explain please

Hey @Mohit_Mishrlll

Once you exit your holdings only 80% of the proceeds can be used to buy stocks. The balance 20% will be available for trade from the next trading day. This is due to Sebi’s new peak margin norm.

You can check on this link to know more.