I don't want to donate money to my nephews medical cost ,I hardly know them.
Did you discuss with any of your family members?
Not yet, I had no connection to him until this thing.
Try to find out something about him or talk to him. Knowing your nephew might change your view.
The problem is that my nephew is always in his room, he's a hermit there is no way I can have an interest in him.
I can see how this would make it difficult.   I would try to find out what made him a hermit and try to connect with an online activity such as video games