Tashkent is currently the capital of:

Uzbekistan

The correct answer is option (2) - Uzbekistan

The Tashkent Agreement was a peace agreement signed in Tashkent, Uzbekistan, in 1966, to resolve the Indo-Pakistani conflict that had arisen after the 1965 war between India and Pakistan. Shastri’s Prime Ministership came to an abrupt end on 10 January 1966, when he suddenly expired in Tashkent, then in the USSR and currently the capital of Uzbekistan. He was there to discuss and sign an agreement with Muhammad Ayub Khan, the then President of Pakistan, to end the war.