How to make a official letter to HR, send back my son to home?

If your son is an adult, you have no right to demand his return to you. You can ask HIM to return home, but you have no business contacting his employer and trying to get him fired. Do you really think he'd be happy if you ruined his job and arranged a marriage for him? He might, of course, but you should ask him. If you don't, and he resents what you did, you're hardly going to enjoy having him living with you.