Father not allowed in house

My mother have 4 children (1 son , 3 daughters) from her previous husband who passed on and my father has also 4 (2 sons 2 daughters) from my mother of whom I’m the eldest from my father side.

My father suffers from nervous breakdown since he was a kid, this never use to be a problem as he will be admitted to psychiatric hospital and after 4 weeks he would be fine. My sister since the age of 15 suffered the same illness.

This does put a lot of strain on my mother when they are ill. Recently my father was sick again and became abusive towards my mother and my step brothers and sisters to the extent where my mother got an interdict thus preventing him from entering the house.

They have been divorced for more then ten years however still stayed together. The divorce was both at the MJC as well as with the government court.

As my fathers brothers does not want him with them due to his illness he stays with me and my other brother. My mother currently allows the step sisters children to stay with her as an excuse not to be alone in the house. But they are never there to look after her as they are always busy with their own things and also do all sorts of wrong things i.e. drink alcohol and use drugs.

My father wants to go back to the house but my mother does not want him to come back as he also used to take drugs and drink.

I need to know what must I do the make thinks right as this separates us from being a family. My father requested the house be sold in order for him to get his share of the house. Would this be correct?