It honestly depends on what you want to do, and based on how much bonus money or bonus percentage the casino site is offering. Only you can decide what is best value for your money.
For example, if Casino A is giving 100% up to INR 10,000 and Casino B is giving 50% bonus up to INR 50,000, the Casino A bonus is better if your deposit amount is the same. If you deposit 10,000 in Casino A, you get 10,000 as bonus money so you get to play with INR 20,000 in total. But if you deposit 10,000 in Casino B, you get 5,000 (50%) in bonus and get to play with INR 15,000 in total.