Father wrote WILL on the Home built by me through Home Loan.

Sir, I am Kanna from Pondicherry. Land is in my Father name, but I built 2(G+1) Storage building through Home Loan 2006. I am the Applicant and I am paying the Home Loan monthly, Rent from the home is taken by my Father, my Father is Co-Applicant. But my Father wrote a WILL without my knowledge in 2012. He Wrote WILL like, after him, the property will manage by Mother. After mother, 50% comes to me, 25%+ 25% of Home will go to my Sisters. But still 8 Years of Loan tenure is there of 11K per Month. My mother is getting 15K as Rent from the Home. But my mother is not ready to give money for Loan. My sisters too not ready to give money. So issue is Home built by me has been distributed to others too. Is the WILL written by Father is correct? Is WILL should written on the property bought by his own money? Home is built my me, but he wrote WILL for that too. My Concern is, I am OK for Mother to stay in home until he lives, concerned on the Home Loan and the money I payed. Please advice How to handle this?