Property transferred illegally

My grandfather had 8 children, of which only two males and 4 females have survived; my father is one of the surviving males. There is a property where my grandfather raised his children which is under dispute. Out of 2 surviving males, one being my father had a transferable central government job so after his marriage he lived in different parts of India. The other surviving male(my father's brother) had continued to stay in the house raising his son with his wife and my grandfather. After my grandfather died(died in the year 2000), my father's brother got the house transferred in his name without the knowledge of my father. These are some of my questions 1. Whether this property would be called as ancestral? There is no record of the owner of the house before 1975 and there is only one record present for the transfer of the property to my father's brother where the executioner was his mother in the year 2001.(mother is not ) 2.whether there can be a criminal case on my father's brother be lodged for cheating my father by illegally transferring the property to his name.