I have planned to visit Gangtok in December 2014 by converting my hometown LTC as per rule. I work in Patna and as there are no AI flights from Patna to Kolkata , I wish to travel Patna -Kolkata by train and Kolkata- Bagdogra by AI flight. But my office is saying that journey from Patna to Kolkata from train is not allowed. Thay say that if I wish to start my journey through train then I should directly go to NJP by train instead of Kolkata to board AI flight. My G.P. is 6600/- . What are the rules in this regard. Pl help