You need to apply for Canadian student visa at Canadian High Commission in Delhi.
It's address is:
7/8 Shantipath, Chanakyapuri
New Delhi 110 021, India
Working Days:
Monday to Friday
Working Hours:
08:30 to 17:30
08:30 to 13:00 (on Fridays)
Contact Details:
Telephone: +91-11-51782000
Fax: +91-11-51782020
Email: delhi@international.gc.ca
Website: http://www.dfait-maeci.gc.ca/new-delhi/