The school houses roughly 500 pupils aged 12 to 18, and admission is based on a competitive entrance examination and an interview with the headmaster. Every year boys are admitted in only two year groups: seventh grade in January and eighth grade in April. As of May 2019, boys from 26 Indian states and 35 non-resident Indians were studying at Doon. The school is fully residential, and boys and most teachers live on campus. In tenth grade, students take the Cambridge IGCSE examinations, and for the final two years can choose between the Indian School Certificate or International Baccalaureate. A broad range of extra-curricular activities, numbering around 80, are offered to the boys, and early masters such as R.L. Holdsworth, J.A.K. Martyn, Jack Gibson and Gurdial Singh established a strong tradition of mountaineering at school. The school occupies the former site of the Forest Research Institute and is home to diverse flora and fauna. Doon remains a boys-only school despite continued pressure from political leaders to become coeducational. Old boys of the school are known as 'Doscos'.