The 'indian legion' is known as Indian National Army (INA) and was led by a former president of the Indian National Congress, Subhash Chandra Bose. Bose was much more radical in hia thoughts than the other leaders of the Congress like Mahatma Gandhi and was arrested by the Britishers as a precautionary measure when the war broke out.he famously escaped from captivity and went across the world looking for support to raise an army that would bring an end to the colonial rule in india. His first hope was the Soviets but it was only the Nazis who seemed to sympathise and provide support. Indian PoWs from the British Indian Army in North Africa were the first entrants in the forces which swelled in numbers because of expats and defectors. The Army was trained, uniformed and stationed in Europe for quite some time. They saw limited action in Netherlands and France. The closest they came to their dream of marching into India was during the Japanese invasion of India after their success in Burma. They moved in with the imperial Japanese army to capture Imphal and Kohima but were met with fierce resistance from the British Indian Army. They couls not spark mass revolts and surrenders as they had expected and in fact these too battles turned the tide in the theatre and led to the recapture of burma by Slim's "forgotten army"

Post war, the British put them on trials for treason and it was then that the indian navy and air force mutinied against their colonial masters. This is considered as a major factor behind the British decision to finally pack up their bags and leave. Thus Bose's dream of a truly independent India finally came true. The former INA members who fought to bring freedom to their nation were pardoned but not allowed to join the army whereas those that remained loyal to Britishers continued and formes the core of what is the Indian Armed Forces today. The INA for all its patriotic fervor was on the wrong side of history.

As a end note its interesting to know that Bose never returned to an independent India. He died in an air crash of a japanese military plane - something that is heavily challenged and disbelieved in India till today. Bose remains an enigmatic figure even today , a bold leader who saw virtue in a militaristic independence campaign- a sharp contrast with his fellow leader Gandhi who is remembered an epitome of non violent struggle.

Typing it on the phone, apologies for any typos

You might find this post by /u/drylaw interesting