Dear Nilesh ji,
Umakanthan Sir has given right advise to you.
I also support the advise given by SRINATH SAI RAM. He has rightly said that mere signing of "No Dues Certificate" will not bar an Employee from receiving (I will say claiming) Bonus to which Employee is entitled.
I would like the quote / share a case law (W.A.No.1478 of 2006) for the benefit of you and the readers. In P. Selvaraj v. The Management of Shardlow India , the Madras High Court was of the opinion that where a full and final settlement was a predicament whereby it was mandatory for an employee to sign it to get any amount, even if it was less than the sum he was entitled to, in those cases the full and final settlement will not stand, and the employee can claim the sum he was entitled to. It also asserted that an employee cannot be estopped from claiming the gratuity amount by virtue of section 14 of Payment of Gratuity Act, 1972, since it has an overriding effect over any other enactment or any instrument or contract.