Cheque bounce

Case Details:- This guy, who is a son of a well-known politician came and approached my father for a partnership regarding a municipal project which could have only been filed by a business with a turnover of crores. My Dad didn't show any interest, after which he somehow started forcing him by showing his reach in the municipal corporation. Due to this, my dad did sign up the agreement (which included those two brothers, along with two other people from the municipal corporation only). Dad got the contract, but he was asked for royalty by the son of that politician, saying that his party is in power and so this royalty is a must. The amount of royalty was rs 25 lakhs, this amount was not given by my father but by that same guy (son of the politician). This guy transferred two amounts of approx 5 lakhs each to our company's account, from where a Demand draft was made and issued to Nagar Nigam, and the rest of the amount was given by the same guy directly to Nagar Nigam in form of cash. Some amount was falling short, so that was given by my dad. But this guy made my dad sign a paper, where it was mentioned that he is giving this money to our company as a loan. My dad, trusting him, signed that paper and handed him over 5 blank cheques as a security for the partnership (cheques were only signed by my dad, nothing else was filled from our side). But when we got the contract, covid arrived, which led to huge losses, and this guy started presenting cheques in the bank, after two cheque bounces, my dad wrote a letter to the bank asking to stop making payments. Hence, all his cheques got bounced and he along with his brother ended up filing cheque bouncing cases (138 and 142) on my dad. When this case was filed, just after two months of filing, my dad suffered a brain stroke due to his constant pressure (Now he is paralyzed too). How are we supposed to get out of this mess, please suggest. Actual agreement papers are with him only, we have just got a scanned copy of those papers. He, along with his lawyer constantly keeps pressurizing us for an out-of-court settlement and even keeps threatening us with regard to our business. By presenting my dad to the court, we have got bail for all the five cases he filed against my dad. Plz suggest what can be done.