Do visit Meghalaya in the month of July and August..best time to visit..if you want help you can contact me in swaroopsamantaray@gmail.com
I will share every details with you
Watch Tripoto's series World of Mg Homecoming: Roadtrip across Northeast India, it has given out a lott of information and is a very amazing travel show - I absolutely love all three seasons of it - It's a must watch
Do visit Sikkim and Meghalaya. However, it will be raining, and travelling in mountains in rains can be a little tricky, so you should plan accordingly.