Subhas Chandra Bose proclaimed the formation of the Provisional Government of Free India (Azad Hind Government) in Singapore on:

Subhas Chandra Bose proclaimed the formation of the Provisional Government of Free India (Arzi Hukumat-e-Azad Hind), popularly called the Azad Hind Government, in Singapore on 21 October 1943.

About the Azad Hind Government:

• Bose was its Head of State, Prime Minister, Minister of War and Minister of Foreign Affairs.
• It had its own currency, postage stamps, courts and civil code.
• It was recognised by Japan, Germany, Italy and several other Axis-aligned governments.
• It declared war on Britain and the United States.
• The Indian National Army (Azad Hind Fauj) became its army.

The Andaman and Nicobar Islands:

• Japan, which had captured the Andaman and Nicobar Islands, formally handed them over to the Azad Hind Government in November 1943.
• Bose visited Port Blair in December 1943 and hoisted the national flag there on 30 December 1943.
• He renamed the islands "Shaheed" (Andaman) and "Swaraj" (Nicobar).
• In 2018, the Government of India renamed three islands in the Andamans, including Ross Island as Netaji Subhash Chandra Bose Dweep.

The Indian National Army:

• Bose took command of the INA in July 1943 in Singapore.
• He reorganised it and inspired its soldiers with his speeches and slogans.
• The INA had regiments named after Gandhi, Nehru, Azad and Bose himself, and a women's regiment.

The end:

• After the defeat of Japan, the Azad Hind Government came to an end in 1945.
• Bose is believed to have died in an air crash in Taipei, Taiwan, on 18 August 1945.
• The trials of INA officers at the Red Fort (1945-46) led to great public agitation in India.

Commemoration:

On 21 October 2018, the 75th anniversary of the Azad Hind Government was celebrated, and the Prime Minister hoisted the national flag at the Red Fort.

Why not the other options?

• ✗15 August 1943, 23 January 1944 and 26 January 1942 were not the date of the proclamation.