First of all your question and statement is confusing: It is;
A. Are you a consultant company, that provides people to work in industry. OR
B.Are you entrusted with the job of giving Salary Slip to employees.
My opinion is:
1. First of all NBFC Sector - what is the agreement with them? Are they teaching you to avoid PF & ESIC? which is illegal and the contract will be void if contested.
2. Secondly, If you are a consultant and providing staff as consultant you are taking care of the staff PF & ESIC and other taxes as are applicable to employees and a statement to that effect should be submitted to the company to submit as addendum to PF & ESIC department for the part of employees provided by you on contract basis.
3. Naturally you know the salary structure of employees that are payable and also what are statutory deductions towards PF, ESIC & TDS and others such as loan or any other agreed deductions, thereby arriving at the Net Pay you remit to the Employees Bank Account.
4. Normally, Time sheet is prepared by contracted company for each employee provided by you and their hours of work every week, month.
5. That is the primary one for calculating their hours to enable you to raise your Invoice for the number of hours your employee worked as stipulated in the contract.
Finally I should stress PLEASE DO NOT TRY TO BY PASS THE LAW OF PF & ESIC Which are statutory for the benefit of employees and which ultimately stand for working force in India to get benefitted.
Your thinking should change for the welfare of employees work force as you are earning out of their sweat and hard work. So don't do such acts, even if you are part of a team. Just resign if such is you job, as you are also an employee in the eyes of law from other angle.