Regarding out of court settlement agreement drafted on a plain white paper

Hello, I am a NRI residing in Australia and got married recently to a girl in India (less than a year). Apparently, the girl married me because of my NRI status and now she and her parents are harassing my family and myself to get the foreign sponsorship or a way to extort money. Her family members recently came to my parents house with women NGO ladies along with some other people and they apparently signed a deal (plain white paper with some witness) that we will pay 25 Lakhs within 15 days. I was not involved in these discussions and my parents signed this because of being terrorized of their threats. First of all, I think this is too much of money that they are demanding. What are my options here :- - What is the legality of this agreement signed on a plain white paper. Can we cancel or move out of this agreement since this is not on a legal notarized paper. Also, I feel this is signed under pressure. What will be the court opinion on this? - Since my marriage has not completed 1 year, so it makes no sense to pay the money right now. If we say, we do not want to pay for the settlement, can court force us to pay this money before divorce and can we challenge it. Please guide us on to prevent myself and my family from this money extortion.