This process of transferring unused funds back is called ‘Running Account Settlement’ or ‘Quarterly Settlement of funds’. The funds are transferred back to the primary bank account mapped to your Trading account.
SEBI has mandated that all brokers transfer back funds to a client’s account if there have been no trades for a period of 30 days. Also, for clients who are trading on a regular basis, settlement needs to be done at least once in 90 days.