Shop in mother's name uncle is not allowing to sell

Dear Sir, My mother is widow and she has an property (Shop) at her name, she purchased in year 2002. As my father died in 1996, the shop purchasing idea was from my Uncle (Big brother of my Father) as he is having running business adjacent to that shop. My uncle idea was let's purchase this shop so he can also use this and run our home expenditure and later in future this shop will be good for children to open any business. There is no rent agreement, nothing, this was just on good will. He (my uncle) has 4-5 shops registered at his name in city and many other properties. Whereas my younger brother and mother don't have anything to run the home. We wants to get back that shop so my brother can do some small business for livelihood. But my uncle is not vacating that shop and asking us to do whatever we want to do. Just need to understand- how long such cases will run in court. Does this come under Rent Controller case? Any chances we can lose the case as well?