Get professional help first.

But, I know a method that seem bad a bit, an uncle at workplace also have this problem with his brother in law. So the inlaw keep beating up his mom and tantrum alot and a colleague of this uncle suggest him to beat the inlaw up. So he did on one fine day. Not beating him half to death or anything. Just enough for the inlaw to stop fighting. After that day, whenever the inlaw want to hurt his mom, the mom just said the uncle name saying will tell the uncle if he don't stop. And he will stop. Uncle said he married around the 90s, incident also few years after married. Until now the inlaw still scared of the uncle. He only hit the inlaw only one time. He been nice if inlaw behave well. Just a bit tantrum he close one one la.

I don't come across any private institute for a center for them. Only gomen lime the tanjung rambutan one. But have to go gen doctor first.