Once a bonus is credited to your bonus balance, there are rollover requirements that are specific to each bonus. Usually, it means the sum of the deposit and the bonus amount, must be rolled over (wagered) a certain number of times on specific bet types, events, odds, etc. Once these qualifying bets are settled as either won or lost and the required amount has been rolled over, the bonus and any winnings generated from it will be transferred to your real funds' balance.
For example, if you place a qualifying bet for 100 INR and it is settled, no matter if it’s won or lost, you will have rolled over 100 INR.
Every bonus has different turnover requirements, so make sure to check the T&Cs of the relevant one.