The Tripura Merger Agreement was signed in New Delhi on

Concept: Princely-state integration into the Indian Union typically involved two distinct dates: the date a Merger Agreement was formally signed by the ruler (or regent) and the Government of India, and a later date on which the merger legally took effect and administration was actually handed over. These two dates are often different and are frequently confused in general-awareness questions.

Application: For Tripura, the Regent Maharani Kanchan Prava Devi — acting for the minor Maharaja Kirit Bikram Kishore Manikya — signed the Tripura Merger Agreement with the Government of India in New Delhi on 9th September, 1949. Under this agreement, the Government of India formally took over the administration of Tripura, and the merger took legal effect, on 15th October, 1949; Tripura was thereafter administered as a Part C state under a Chief Commissioner.

Why the other dates don't fit:

• 15th October, 1949 is the date the merger took effect and administration was handed over — a later milestone, not the date the agreement itself was signed.

• 15th August, 1947 is India's Independence Day, unrelated to Tripura's own merger process, which was concluded separately more than two years afterward.

• 9th November, 1948 does not correspond to any documented milestone in the Tripura merger process.

Result: So the Tripura Merger Agreement was signed on 9th September, 1949.