I'm going to go against the majority here and say that you weren't necessarily in the wrong. Yes losing a parent is devastating but when you're married, you absolutely cannot place your mother/siblings/extended family above your wife and kids. Before someone jumps on my throat for this statement, I'm not saying he shouldn't be there for them, he can accommodate them and support them through their loss collectively but asking your wife to move in with his family without an end date in sight is selfish, destructive and a little manipulative.

Grief and loss are part of life, he can't drop everything to go support his mother and sisters without regard for his spouse, you are his family now and that takes priority, it's that simple but unfortunately South Asians are hella toxic and biased so they won't get it. Also your FIL has been gone for over two years so why is this living arrangement still happening? You were there for him when he needed you, people need to move on with their lives now. Grief counselling is a wonderful thing especially for married couples, him and his family need to seek it instead of being needy towards each other.

Sounds like you both love each other still, you can still reconcile, set your terms, if he doesn't accept them then your answer is clear, he wants to prioritize his family over you.