To avoid getting in stuck in my brother and his wife's case, which I think will definitely happened.

The case is that I live with my family with my brother ,sister and parents and my brothers daughter and his daughter of age of five, my brother and his wife fights immensely and my brothers wife puts aligation of him having a extra marital affair & she abuse his husband in most disrespectful possible way ,and any one of us other than his husband never raised a hand on him ,even several times she try to beat his own husband and she hurt herself very badly several times and she beats his forehead with wooden Planck till it's swelled up, and threat us all of making us all put into jail, and trying to hang herself several times I never stood up in these matters till the day she accused me of beating her in the panchayat in front of my and her own family, I am willing to prepare for government services and I'm afraid of sticking in between all these cases because they both fight very badly every one or another day I know get used to it but I can not let myself being in in the risk of getting in all these legal caSes without any fault of mine. And my family believe that these things happens in marriages but it's too much.Just tell me how can I secure myself in this situation.