Kerala has 3 International airports.
Foreign students who do not have direct flights from their countries to Kerala may fly to one of the major cities Delhi, Bombay( Mumbai), Banglore or Madras(Chennai) and then take domestic flights to Kozhikode and then on to Kannur by train or bus.
Alternately you can also travel from all these places to Kannur by train. Buses also connect Mumbai, Madras and Bangalore to Kannur. Bangalore is the city closest to Kannur.
The Kannur International Airport is expected to become functional by 2015.