On January 21, 1972, Tripura, Manipur, and Meghalaya became full-fledged states under the North Eastern Region (Re-organisation) Act, 1971.

• Manipur was a princely state that merged with India in 1949, and achieved full statehood in 1972.
• Tripura was a princely state until 1949 and became a full state in 1972.
• Meghalaya was initially an autonomous state within Assam, formed in 1970, and achieved full statehood in 1972.
• These states celebrate their Statehood Day on January 21 each year, marked by cultural programs, parades, and events.