Before the 2020 merger of Union Territories, Silvassa was the capital of

A Union Territory (UT) is an administrative division of India governed directly by the Union (central) government. Most UTs have a single designated capital city that serves as their administrative headquarters -- the seat of the Lieutenant Governor/Administrator and local administration -- though a few exceptions exist (for instance, Jammu and Kashmir has historically used two seasonal capitals, Srinagar and Jammu).

Silvassa was the administrative headquarters of the Union Territory of Dadra and Nagar Haveli, which existed as a standalone Union Territory until 26 January 2020, when it was merged with Daman and Diu to form the single Union Territory of Dadra and Nagar Haveli and Daman and Diu (whose capital is now Daman). Under the pre-2020 structure that this question is framed around, Silvassa was the capital of Dadra and Nagar Haveli.

• Lakshadweep's capital is Kavaratti, not Silvassa.

• Daman and Diu (its own separate Union Territory before the 2020 merger) had its capital at Daman, not Silvassa.

• Arunachal Pradesh is a full state, not a Union Territory, and its capital is Itanagar.

Hence, Dadra and Nagar Haveli is the Union Territory whose capital was Silvassa, under the pre-2020 union-territory structure.