Explanation : 

I. Arunachal Pradesh: The capital is named after a fort, and the State has two National Parks

– Capital named after a fort: Itanagar, the capital of Arunachal Pradesh, is named after the Ita Fort, which literally means “Fort of Bricks” in Assamese.

– Two National Parks: Arunachal Pradesh has two National Parks: Mouling National Park and Namdapha National Park.

This pair is correctly matched.

II. Nagaland: The State came into existence on the basis of a Constitutional Amendment Act

– Nagaland was formally inaugurated as a state on December 1, 1963. Its creation was based on the State of Nagaland Act, 1962, passed by the Parliament.

– Simultaneously, the 13th Constitutional Amendment Act, 1962, was enacted. This amendment inserted Article 371A into the Constitution, providing special provisions for Nagaland, which was crucial in facilitating the creation and defining the special administrative setup for the new state.

This pair is correctly matched.

III. Tripura: Initially a Part ‘C’ State, it became a centrally administered territory with the reorganization of States in 1956 and later attained the status of a full-fledged State

– Initially a Part ‘C’ State: After merging with the Indian Union on October 15, 1949, Tripura became a Part ‘C’ state.

– Centrally administered territory with reorganization in 1956: With the reorganization of states in November 1956, Tripura became a Union Territory. Part C states were administered by a Chief Commissioner appointed by the President.

– Later attained the status of a full-fledged State: Tripura attained the status of a full-fledged state on January 21, 1972, by the North Eastern Areas (Reorganization) Act, 1971.

All three pairs are correctly matched.