Hello Nikhil, I think North East part of India is the most amazing part of India. You can definitely cover Meghalya, Sikkim, Gangtok, Kaziranga, Arunchal Pradesh.
1 week isn't enough to explore the beauty of North East India, I would suggest plan 2 to 3 nearby places and then explore it, do likewise to complete it all!!
Hi in a week you can not cover all the beautiful states of NE.
However you can stick to 1 or 2 state and cover it entirely.
Here are the few recommendations - Sikkim - Gangtok,Lachung, Yumthung, ZeroPoint, Lachen, Gurudongmar Lake, Tsongmo Lake, Nathula Pass, Baba mandir, Zuluk, Pelling. Meghalaya - Shillong, Cherapunjee, Mawlylong, Dawki Assam - Kaziranga National Park ( a must see), Majuli, Nameri National Park Arunachal Pradesh - Bhalukpong, Bomdila, Dirang, Sangti, Tawang , Bumla Pass, Ziro Valley.
Hi NIkhil, It depends on which season you are going - If you are going on sept-nov autumn you can visit Arunachal Pradesh and covering assam. Post monsoon also a good time for Meghalaya as greenish mountain accompanied by majestic numerous waterfall is treat to the eyes and you can visit Kaziranga .
if you are traveling in winter then sikkim is the best option to play with snow.