An Adventure Camp (organized by Govt of India) in Roing (Arunachal Pradesh) was a godsend. And I decided to skip my final semester exams for this. Best. Decision. Ever. From west to east train journey is the best option. There is no direct train to Arunachal, so you have to take a combination of bus and ferry.
A bus breakdown gave the chance to explore a quaint village, see traditional bamboo houses and chat up with the locals. The people were suprisingly self-sufficient had their own poultry, fisheries, farms and productions.