What do you need for an international driving permit?

As per THE CENTRAL MOTOR VEHICLES RULES, 1989 of India:

An application for an International Driving Permit shall be made in Form 4-A and shall be accompanied by—

valid driving licence issued by the licensing authority (under these rules);
- appropriate fee as specified in rule 32;
3 copies of the applicant’s recent passport photograph;
a medical certificate in Form 1-A;
valid proof of Indian Nationals; if valid proof of passport; and
valid proof of visa, wherever applicable.

Check here link various forms