The journey from Gangtok to Vijayawada covers roughly 1700 km. You must first reach NJP or Bagdogra. From NJP, you can take a direct train to Vijayawada Junction. Flights from Bagdogra to Vijayawada usually connect through Hyderabad or Bangalore.
Total Distance: 1700 km by road, 1400 km air distance.
Ensure you book a train that stops at Vijayawada Junction.
Hyderabad is the most convenient hub for this connection.
October to March for pleasant weather.