Is shunning a brother whose wife prevents him from praying, visiting his family, curses them, prevents him from going to the mosque, and he listens to no one but his wife, and shows hostility towards religion; a correct and legally acceptable action?

The brother must obey his father and separate from his wife if advice, abandonment, and physical discipline are ineffective with her. Abandoning prayer entirely is apostasy from the religion. Discarding religious books with the intention of insulting the verses and hadiths is also apostasy; if there is no intention of insult, it is a grave sin. Abandonment is not desired for its own sake, but for the benefit it brings. If it will be beneficial, then do it; otherwise, do not. Continue to advise them with gifts, kind words, and supplicate for their guidance. If he persists in his state, there is no blame in cutting ties with him.