Can grand daughter claim on self acquired property of grandfather

My father died leaving without any will on his self acquired property. I am daughter to my father and i have one brother and one sister. My sister is not alive and my mother is still alive. My question is, can the daughters (one major and one minor) of my expired sister claim on the property of my father? Additional info: My sister's husband married after the death of my sister. The property is in Chennai. I am currently living in US. My brother is not supporting my mother. My mother has no earnings and she decided to leave the land for joint ventures. One house for her living and one for the rental income for her living expense. Now, my expired sister's husband filed a case on behalf of his daughters claiming 1/4 (equal share of my sister). Just want to understand, if the grand daughters of maternal grand father has the equal rights of expired mother? Secondly, can my mother sell the entire property, without the signature of grand daughters and only with the signatures of living son and daughter?