How to get maintenance for parents

Where will my mother go to appoint a lawyar on free of cost? We have a small plot of land. The ownersof the land are i,myself, my mother & my younger brother. We have 3 rooms on rent whic is the source of my mother. When mother was with my brother then my brother took all the earnings coming from the rent bt just a month ago my brother & his wife physically assulted her & pushed her out of the house. From that day she started to live with me. I am divorcee. In this situation i appointed a nurse to look after her on the salary of 7,000. She has medical expense as she suffering from diabatc. Apart from such expenses she has to pay electricity. I am a private tutor. My younger brother only allowed one room on rent bt others two he is enjoying. In this situation its quite impossible to maintain my mother. Whenever we ask him to handover others two rent he & his wife burst into physically torture on us. My mother want justice.