Options for Handling Final Settlement
You have two options: (1) the amount is small, and (2) the amount is big.
If the amount of F&F is small, do not sign any agreement or give any blank cheque, and be prepared for losing this money. At the same time, keep your efforts of recovering monies on by reminding them weekly, by all means of communication—phones, emails, letters—and mark cc to the labour inspector, factory inspector, company's Directors, etc. (Actually, do not send these CCs; it should appear only on originals, cc to:…). Do this exercise continuously for two months, three months, and so on. At one point, your HR will get fed up, and looking at the smaller amount, to avoid nuisance, they will make payment.
If the amount is big and the company is insisting on an agreement as well as a cheque, try to remember your past working days with them. You must have seen during your tenure with them whether they are really serious and particular about compelling this kind of documentation, and unless the same is done, they do not make F&F of employees (though this is illegal). If at all, the answer is YES, you do not have any option but to fight legally and get your monies.
My suggestion is to think of the proper order in which you should move ahead. Do not think to give a first legal fight and then recover money. This situation will make you pay heavy amounts from your own pocket towards legal expenses, and also tremendous tension about whether you will be winning or not.
Think the other way… Get the money first and then go for a legal battle. Sign the Agreement, give them the cheque. Get your monies cashed to your account (which we presume is a big amount… say 1 lac, etc.), and then you yourself send them a lawyer's notice that the Agreement signed by you was not willful and also without knowing the contents of the same, and of course, which is illegal by our Constitutional rights. Make an immediate stop payment of your cheque. And then relax, not totally, but to a great extent.
Here the money is already in your pocket, and out of the same kitty, some portion, say 10%, you keep aside for court matters, that too if the company really decides to harass you. And the remaining money you can enjoy as per your wish. (In the first option above, or otherwise, we had decided to forgo the F&F if the amount is small. Now the same small amount, you are spending on your Lawyer).
Another situation, since we presumed the F&F amount is big, say about a Lac, keep this money directly in a Bank's fixed deposit, and on the interest earned from the said FD (It will be about 10000/annum), you will be able to pay your lawyer's fees. In a worst-case scenario, if you lose the case, you may have to pay some penalties to your company, and your Bank FD will take care of it.