Market pre-open at IST 0900 hrs, Where one can request orders or modify orders with the intend to start matching immediately after close of pre-open order entry. Stock market trading hours start from IST 0915 hrs and stock market closes at IST 1530 hrs, This is a normal trading time where you can buy or sell shares at real time. Post closing session starts from 1540 hrs to 1600 hrs, where any transactions fail to settle are been performed by exchange like day trading stock has to be closed on the same day, Exchange will settle the trade if user fail to do so and in many more such discrepancies circumstances.