Which country's malcontents with the British Empire provided the Japanese Empire a complete Army Corps of soldiers during WWII?

The Indian National Army (INA; Azad Hind Fauj) was an armed force formed by Indian nationalists in 1942 in Southeast Asia during World War II. Its aim was to secure Indian independence from British rule. It formed an alliance with Imperial Japan in the latter's campaign in the Southeast Asian theatre of WWII. The army was first formed in 1942 under Mohan Singh, by Indian PoWs of the British-Indian Army captured by Japan in the Malayan campaign and at Singapore.

The INA fought along with the Imperial Japanese Army against the British and Commonwealth forces in the campaigns in Burma, in Imphal and at Kohima, and later against the successful Burma Campaign of the Allies.

The INA numbered approximately 43.000 troops. Enough for four Divisions or one Army Corps (25,000 To 50,000 troops).