Forcibly taking signature on a post-dated cheque for Rs. 2.90 cr. as security against future loan

An investor approached me to trade on his trading account (stock market) and shared his log-in id and password. However, on account of failure or crash of broker's software and high volatility and other reasons, the investor lost money in the trade. After a few days, the investor and his people (agents) called me to a hotel and told me that the investor would be giving me a loan of Rs. 2,90 cr for trading from which i should share profit with him and forced me to give a post-dated signed cheque as security for the proposed loan, I had no option but to give him under duress a post-dated signed cheque for Rs. 2.90 cr with a letter mentioning that it is security for the proposed loan The investor had also assured me that he would not present the cheque to the bank. After a few days, the investor started threatening and intimidating me on phone saying he would present the cheque to the bank if i don't return his lost amount. When he said this, I issued stop payment online instructions to the bank. He also threatened that he would send his men to force me to handover my original property documents. I have neither taken any money from him nor got any profit share from him. What kind of legal protection i have in this situation? Can I file a criminal case against the investor and his people for forcibly obtaining a post-dated signed cheque, cheating and threatening me and can i stop him from proceeding to present the cheque to the bank and file a case against me? I shall be highly grateful for your legal advise in the matter or any other assistance.