is generally considered a good idea to document agreed-upon terms, provided it is done fairly. It serves as a record of intentionand can prevent future "unwarranted claims" by acting as evidence of what both parties considered reasonable at a specific point in time. 

Sir, if you are anticipating a divorce case coming to you, executing an agreement is not going to safeguard you, as it will be treated as a pre-calculative move of yours in order to avoid maintenance or alimony. Moreover, the agreement entered into out of court has no legal sanctity as no oath is administered to the parties entering into it and it is a general presumption that it might have been executed under coercion or misrepresentation. It might in fact work against you if not favouring you.

Instead, you may opt for a pre-institution mediation, which has more legal sanctity and the mediation deed prepared therein is almost equivalent to a court's decree.

That is why, you should get an agreement (settlement deed) made through the process of pre-institution mediation, which doesn't require any case actually having been filed. It's a process that is going to keep you safeguarded when you go for a mutual divorce. 

A post-nuptial agreement in India is not a complete legal shield in a Hindu marriage; the Family Court still has power to decide permanent alimony, and such orders can later be varied if circumstances change.

It is still a good idea only as evidence of a fair settlement, if it is jointly signed, voluntary and with full financial disclosure; but a one-sided affidavit or waiver can be viewed cautiously, and private terms cannot conclusively override matrimonial rights fixed by law.

Next step you may consider

Please get a proper matrimonial settlement/MOU drafted and signed by both sides, and later place the same before the Family Court in the mutual consent proceedings

India does not formally recognize post-nuptial agreements as automatically enforceable contracts.
Under Hindu Marriage Act, 1955 and personal laws, marriage is not treated as a purely contractual relationship
Courts retain discretion over maintenance, alimony, custody, etc.
Any private agreement cannot override statutory rights
Also, under Indian Contract Act, 1872:
Agreements that restrict legal rights (like maintenance) may be seen as void or against public policy.

Any agreement finalized in a mutual consent divorce becomes a part of the divorce decree hence any party trying to reopen the subject matter at a later stage will not be entertained by court or law for any reason. 

Hello,

No, a post nuptial agreement doesn't have any value before the court. Your wife may relinquish her rights by agreements but in court she can claim it as per law. 

So what you have to do is to ask her to make a statement in the petition that she didn't have any claim and that she is competent to maintain herself and doesn't depend on others for her necessity.

Hope this helps.

Regards