My GrandFather has been gone missing during train journey

My grandfather and my parents were traveling from our village Gonda to Ahmedabad. He boarded Sabarmati Exp. on 15/05/18 and had dinner together around 10 pm, while the train was reaching Ratlam Jn and slept on their allotted seats. My father woke up around 2 am, while the train was reaching Vadodara, and noticed that my grandfather was not in his seat. nSince my father & grandfather slept after Ratlam Jn, the train crossed three stations - Meghnagar, Dahod & Godhara. I visited all three stations inquiring if he missed the train or if any accident happened. Godhra station's CCTV confirmed that while our train left the station around 1 am, my grandfather was still there at the station. So finally, the Railway Police filed a "missing report". It's been over 5 years & there is no clue what happened to my grandfatherMy grandfather owned farming land where my uncle is currently farming. Please advise, how my father & uncle shold claim the inheritance land and house, equally.