When you hire an employee, you need to pay them, whether they are in probation or not. That is the law in India specified in the Payment of Wages Act. Additionally, you have to pay above minimum wages. The only situation where you may not pay someone is if they are very short-term trainees. In this case, they would be actual trainees here to learn and not expected to deliver any significant results to the company. Even if you are hiring apprentices, they have to be paid.