Undivided hindu family property matter

Hi, In our village, we have a property (House, Agricultural lands etc) to which my father was made manager 50 years back. My grand father has 8 childrens (5 sons & 3 daughters) out of which only my father had stayed in this property since 50 years. As per the property document in grampanchayat, it contains all 8 childrens names and my father as manager. My father made developments in this property all these years on his own expenses. None of his other brothers/sisters has never made any contributions in this. Now my father passed away and so as his 3 other brothers & 1 sister, the living brother and their sons want to take possession of the property. My mother and one sister are still staying in that property & maintaining it. All documents like Property tax bill, electric bill, gas connection and some other documents is the name of my father only. My question is that can my father/mother or me and my sisters will be considered as the owners for this property for being stayed & developed this property from 50 years. All these years my fathers income was only through agriculture. I seek your valuable advice on this matter. Pls help me