siyali and utkarsh

Actually friends I didn't get one thing...when that mother was explaining about siyali and utkarsh to the Princi whether did she say that they are not blood related???also I took it as since both of them came to orphanage together and siyali's last name is rajput they thought that utkarsh last name was also rajput...Plzz clear it coz I just confused with these things since my language is not Hindi but can understand only little