As per the PIB at http://pib.nic.in/release/release.asp?relid=55628 dated December, 10

So far, seventeen airports in the country have been accorded “International Status”. These airports are Ahmedabad, Amritsar, Calicut, Chennai, Guwahati, Jaipur, Kolkata, Thiruvananthapuram, Bengaluru, Hyderabad, Kochi, Delhi, Mumbai, Nagpur, Goa, Port Blair and Srinagar. … Some airports are notified as Customs airports which can also cater to international flights. The customs airports are Varanasai, Tiruchirapalli (Trichy), Patna, Mangalore, Lucknow, Gaya, Coimbatore and Pune (civil enclave).

The following map shows the above airports. As one may notice there is a huge part around Odisha, Northern Andhra Pradesh and Chhatisgarh that is not served by an international or customs airport. To serve those regions it is important that international connectivity is brought to Bhubaneswar airport.