I am giving an example of Shops & Establishment Act of AP and Telangana and most probably even the TN S&E Act will be on the same lines:
Chapter VIII Section 37. Wages for overtime work :- Where any employee in any establishment is required to work over time he shall be entitled, in respect of such over time work, to wages at twice the ordinary rate of wages.
So if you happen to give a compensatory leave it will not be commensurate with what has been given in the Act.
So long as you give something better than what is stipulated there should not be an issue.
Thanks and Regards
6th December 2018 From India, Hyderabad