Property dispute within Brothers and Sisters since so many years

The dispute is within my mother's side as they are 6 brothers and sisters who have dispute over 500 sq yard plot with some part constructed in AGRA.The property owner was my Nanu and Nani who was died some years back. Now the dispute is that one Brother of them is against 5 others.2 brothers are still residing there in Agra same place. And 1 sister(my mother) and brother living in Delhi.1 brother living in Jodhpur.1 sister living in Bundi,Kota. The brother who is against all others is the real one who is creating problem and disputing the share unequally all the time we all met for discussion. And this is even legally brought to the court as well in Agra civil court and the case is running from both sides from past many years. what should we do in this sutuation to resolve the problem as soon as possible?