If you wish to travel to Tibet in China, you are required to join:
A. Pilgrimage Group: Group of pilgrims is organized by Ministry of External Affairs, Government of India and authorized Indian travel agencies. The Embassy accepts visa applications of pilgrimage groups submitted by the Ministry of External Affairs and authorized Indian travel agencies only. Or
B. Ordinary Tourist Group: Tourist group of Indian nationals can be organized by local Indian travel agency with arrangements from China. You can try to contact China tour agency(https://www.travelchinaguide.com/) for details. Group visa may be issued only after the Embassy has received approval from Tourism Bureau of Tibetan Autonomous Region.
Otherwise, it is very hard for him to apply for a tourist visa to China.