Husband not giving maintenance and living separately without divorce

Actually my mother is struggling with few court cases against my father.she is only 12th passed.and my father is a principal in kendriya vidyalaya.i hv done an intercast marriage.so from that moment only my father is blaming to my mother and to my brother,who is working in an Indian army that both of them made me to run from home.which is not at all true.i hv done this marriage from my own wish.now my father is staying separately from my mother and not giving single penny of money.she is staying alone with my another youngest brother who is studying in class 10 only in that principal quarter.my father is not paying for his studies also.now my brother only bearing all the expenses who is in army.from last 3years she is continuously struggling with the cases at kanpur and staying in the quarter only despite having own house in kanpur because my father is not ready to give any share from the property neither to my mother nor to my brothers.