Dear Bhaskar,
I am totally in disagreement with what you had suggested. I am of the strong opinion that in case we are engaging somebody as a contractor, then all the terms and conditions should be enumerated in the contract itself, including the effective date of the contract, validity, payment terms, etc., inclusive of an indemnity clause. However, is it practically viable to hold the contractor accountable for any non-compliance at a later stage as you suggest that all payments, such as Bonus and Gratuity, will be made by the contractor? The contractor is not going to pay anything from their pocket unless and until it is not paid to them by the principal employer. Nonetheless, for the sake of our mental peace, we can obtain an undertaking from the contractor as follows:
Undertaking
Received with thanks from M/s ____ a sum of Rs._________ towards full and final payment as per the terms of the contract dated_________. With the receipt of the above amount, I hereby declare that nothing stands outstanding against M/s__________.
I further undertake that I have made all the compliances under various labor laws as applicable, and in any later stage, if any liability is fastened on M/s_________, I will indemnify the same.
Thank you.