Sikkim was not included in the seven sisters state of India. The states which lie in the north-east region of India are known as seven sisters.
The seven sister states includes - : Arunachal Pradesh, Assam, Manipur, Mizoram, Nagaland, Tripura, and Meghalaya.
The seven sisters states were inaugurated in 1972, whereas Sikkim the 8th state become a state in 1975. 3 years after the term seven sisters was coin.
