We have an ancestral property (a bungalow). We are 4 brothers and 2 sisters owners of ancestral property.?

We have an ancestral property (a bungalow). We are 4 brothers and 2 sisters owners of ancestral property. We sisters are married and staying with our in laws. Ground floor is occupied by my four brothers and their families with in-built walls separating their families. First floor is occupied by our tenants. The rents are taken solely by my elder brother. The tenants are not staying but they come and give the rents and take the receipt on time. They do not have any doents (only the rent receipts) to prove that they are the tenants. My father expired without leaving a Will. We got the ancestral property transferred on my mother's, brothers' and sisters' name. (7 names in total) We have the property card to prove it. My mother expired recently. We two sisters are married and staying away from our ancestral property. With my mother's death and we sisters staying away, my elder brother is trying to take over the first floor (our share of property) for himself.Kindly tell me what is the legal action to be taken to stop him from doing so?