Forcing same shift timings more than 4 months! Most urgent !

When you are under private employment, you can only request and convince the manager and any such quoting legal process etc may bring in additional problems.  Please search in google as there is an association for computer software engineers that offer practical guidance under experts in law at Bangalore.  Contact them and perhaps they can be able to provide you correct guidance as they might have guided many others experiencing the same problem like you.

You may take up the matter with the Managment and if need be bring the matters to the Notice of the Human Rights Commission.