What to do when ex-boyfriend threatening to get sexual with him

Respect Sir, I'm from Mumbai I was in a relationship just for 3 months with a guy. I met him first because of my younger Sister. He is my Sister's boyfriend friend. I broke up with him because of his uneducated behavior and family issue .he only wanted physical relationship always and I can't fulfill it everything. So I broke up with him and now he is tougher me to with 2 conditions 1 to have sex again with him or if I can no he will tell everyone that's I have been physical to him .he is tougher me everyday and every single second and in this my younger sister is helping him . He is tougher me alot.he told me to meet on 14 July I meet him he took me again to a room.and ask me to have sex but I said him no . But again he is asking me to come on 28 July to room and ask me to start with everything or else he will come to my home .he is tell me that's he have a video or if I'm not accepting his conditions he will not leave me . He is tell me don't go to police.