Legacy heir

I want to know about a property house I am living in for the last 30 years at Ferozepur city of PUNJAB. My house property is Registered in my husband's name. My husband died 3 years back. No will left. He was medically sick. He was on dialysis. His both Kidneys were failed. We had no children. My father in law 86 years old got legacy vasiyat of this house in his name and done his legacy vasiyat further in name of a grand son from his another son brother of my husband. He could do this on the basis of 1. We had no children 2. We had a divorce 10 years back in 2007 as my husband forced me to get divorce papers made Because he wanted to have another wife for bearing children showing divorce papers. But he could not make any children born out of his lust from many women he started living with them time to time without marying any of them. After considering my objections he once again acted upon and got registered our same Marriage in Chandigarh court in 2010 that originally happened in 1982. What is you advice for me on how to get my house property legacy vasiyat cancelled from my father in law's name and get it dine on my name in no time. I need to get it done at tbe earliest possible because an aging father in law may die any time leaving this status in favour of his grandson for ever.