Is there anyway for my mother to get custody of my grandmother?

well my grandmom been liveing with us seen i was 1 i 21 now. anyway my grandmother been in the usa for many yr. she have old timer. and her older son want to sent her to puerto rico been more grandmom dont ever want to go back there. and my mother dont have custody of her. so is there anyway de my mother can get custody right. in newark nj