Understanding Overtime Regulations in India
There are rules regarding overtime, both in the Factories Act and the Shop and Establishment Acts. Depending on what applies to you—such as which state you are in—the actual rules may vary.
In general, working beyond 9 hours a day or 48 hours a week is considered overtime. Overtime is to be paid at twice the ordinary rate of wages (check the research button, it's discussed before). There is a limit of 50 hours a quarter, 2 hours a day, or 6 hours a week, depending on which state you are in and whether it’s a factory or a shop/establishment.
You also need to ensure that overtime does not result in the employee doing regular 12 or 16-hour shifts under the guise of overtime. You will get into serious trouble for that.