Relatives forcefully occupying my father property how to get it back

My father took a loan from a nationalised bank (where he was an officer and in january 2017 expired/died while in service as an DZM at a prime age of 58) and built a house nearly 20 yrs back. My grndparents were alive and lived there while my father and all of us as in my mother and sister, were on a move around india and abroad due to his transfers owing to his job as a banker. After my grabdparents passed away in 2002 and 2004..my father was preparing for another transfer to the UK. My father's younger brothers and older brothers and their families plus my father's sister and her children were on and off living at our house in cuttack (odisha). My father being the only one on whom everyone of them depended since my father had a stable income and had a big heart to support everyone financially and emotionally, was always exploited by these above persons (his brothers and sisters). My father had allowed them to live in good faith but they have not moved out nor allowing us to stay. What should we do?