sheltering 17 yr old boy

Sir,

My relatives are in a fix. A metally challeged boy, 17 years old has come to their doorstep, since his parents have abondoned him on the street. He pleads us to get him to his father. But the father is absconding,a fter using violence against the boy.

What are the boy's rights? Can a parent abondon a child.

Will it be a problem for my relative , if they keep the boy?

How to legalise this?