What can I do if someone is threatening me to implicate me in a false court case?

My 76-year-old father who is a retired govt servant, gave his only house to me via a registered gift deed 2 months ago. while he was getting the gift deed draft prepared, I asked him to add 2 conditions in that deed, a) till he is alive donee cant transfer the said house or lease/rent it out b) as he is a heart patient thus I will make sure that he is taken care off. Now, after 2 months he is demanding from me 40 lakhs so that he can pay it to his son, who as per him is not happy with this gift deed. I told my father that I don't have that much money and being a retired govt servant he is getting 1 lakh rupees as a monthly pension so he can take care of all his expenses. He is threatening to file a 420, 315, 334 case against me if I don't pay him the money, stating that he is old no one will trust me and he will make life a hell.