Dear Ramu,
Have you appointed the apprentices under the provisions of Apprentice Act of your state? If yes, have you read the provisions of the act?
Apprentices are not regular workers. They work to take on job training. They are paid stipend and not the monthly wages. Nevertheless, question arises as what they can learn in night shift, why they cannot learn during day shift? Is learning that will happen in the night shift is part of their curriculum? Please note that making apprentices to work like regular workers is illegal.
You may call Employment Officer, whose generally office is at Employment Exchange to settle your query. He will be the right person to guide you.
Thanks,
Dinesh Divekar