Property dispute in family what to do

My father has 3 brothers (aged 50-60). My grandfather lives lavishly. My grandfather owns 3 shops and 1 shop is owned by my elder uncle. On papers, we are a joint family but in real life each of the brothers lives seperately with their wives and children. My elder uncle controls 1 shop which is legally my grandfather's and my father controls the one which is legally named after my elder uncle. The other 2 shops are given on rent and the money eaned from it is given to take care of the other 2 uncles who live in villages who don't work. My elder uncle has taken a loan on the shop that he controls (legally my grandfather's) and has brought a flat, cars, and land. However, my grandfather doesn't provide my father with any financial help to even start a business. My father doesn't own a flat or any property so we live on rent. Our financial position is very weak. Me and my younger sister are yet studying and can't support our family as well as our education. Can we take any legal action?