Family dispute

Hi , My father had a joint Family with 4 brothers and 5 sisters. The elder brother came to Delhi and bought a house and called his family to come and live there. He opened a shop for his 2 brothers in the name of mother, whose amount is repaid by both brothers with time but not changed on papers . Now the elder got retired and the cost of household is paid by both brothers for 16 yrs for 16 members. Now their sons sold the property and bought a big house for them and a small one for 2 uncles family.both uncles have never thought of themselves thus never saved money or bought a house for them. After Demise of father ,sons wanted the shop and house back from their uncles. They are torturing them by sending legal notices , changing name on e.b, doing it's registry in their mothers name . What should both uncles do to get their right from property as they have completed 11 yrs in small house and 26 yrs in shop. Pls help and reply asap.