Defining flat ownership in mom & me

I have purchased 3bhk worth Rs 1.5 Cr flat in mumbai in 2013. While doing initial part payment to builder 7 lacs rs money transferred form my mothers account i have paid that money to her after 1 year. (total 24 lacs i have paid her since from property purchase) Now my mother wants her share in this property wrt that 7 lacs initial contribution she wants money as per todays valuation. (Actualy my other two brothers forcing her to take share in this property) Her name is not on agreement i had given her power of attorney but that all canceled now. because of her day today touchier i left that flat and i am staying in rented house with my wife and daughter. Now she alone stays in that 3bhk house. i asked her to go and stay in our fathers house which she has given it on rent. my father is no more. she says she will stay in this house because she is owner of this house as she paid initial 7 lacs rs. and she is also saying that she will file case against me that i am not taking care of her. I have two elder brothers they are in mumbai but she dont want to stay with them also and she also dont want me to enter in to home with my wife and daughter. (She is government servant as a clerk) my one elder brother utilizing this property by arranging his shop boy's stay in this my house. I am working in merchant navy and unable to find solution on this. plz help.