Advice in case tenant threats to transfer property and vacate shops.

I am the 1/6 Share holder of joint 4shops situated at chembur, my family was threatened by the tenant to sell the property to him or he will not vacate the shops. So we signed mou to buy property in his wifes name, he also fraudulently took signature on power of attorney in his name, which only i cancelled later on. By striking my signature off and name off the original document taking a video.I was threatened by the buyer that I will face the consequence. He has mentioned in mou he will be filing heirship certificate but is not doing anything and now has asked me to stop calling him, I told him I will file a complaint ,he again threatened me and my husband. I know every one at Chembur police station, I have been in bomb blast, I am a tadipar, I have been in jail several times, I am not afraid of police. I went to police they say its a civil go to court??