How to secure hundred percent share in mother property

I'm a Hindu by caste. I'm a Male and i have 3 sisters, my father passed away long back and mother is staying with me. All my sisters are married. Now the situation is that my mother doesn't want to transfer the property in my name until she's alive and also she wants to give some share to each of my sisters. She has neither created any will nor has she filled up any nomination form. Me and my sisters have agreed to settle down the matter by me paying Rs. 5 lakhs to each of them, and they having no further interest and involvement in the property. But the problem is, if i pay them 5 lakhs and just make up the will which would say that the property would transfer in my name after my mother's death, or i fill a nomination form with my name as 100% nominee, the will can be changed later and it could be a problem to me then. Please suggest what should be done?