Hi My son is studying in Thailand and he is Indian Citizen means born in India. Can he write IIT and will the rank be given and admission done under normal process

To best of my knowledge, YES, he can write the answer....be sure that he perfroms well in order to get an admission at IITs/NITs and if he does not perform up to the mark, then he may definitely make it some other chosen one educational institutions which are offering Engineering programs....I may suggest some names, you can consider the oficial weblinks to cull out the required information:-   Banasthali uni, Banasthali,..............Lovely Professional Uni, Phagwara,..............College of Engg and Tech, Bhubhneshwar,.....Maharishi Markandeshwar Uni, Ambala