Hi @Jatin_Dubey,
For equities, the normal market timing is from 9.15 am to 3.30 pm, but the exchange starts collecting orders from people at 9.00 am till 9.08 am called as pre market window, during this time, they collect the orders from the public and during the next 7 minutes before markets open, they match these orders to decide at what price the stock will open for the day at 9:15. Hope this helps
For more visit zerodha.com/varsity
Cheers,
Lindo