It's very weird, because even Bose himself was ideologically a democratic socialist, or probably more similar to Franklin D Roosevelt. It would be best to keep the current ideological leaders they have in the game because India did have communists, and India did (does) have falangists (Hindus of course, instead of Catholics, but the mechanics are still the same). It did have fascists and nat. socialists too, but not enough to matter.
Realistically, India has many more choices of "likely" or "rightful" leaders than many other countries in the game, for each party. Bose makes the most sense for democratically aligned parties, because while he was an Axis collaborator and approved of German and Italian authoritarianism, he was staunchly opposed to Nazi racialism, and only saw authoritarianism useful during war and sought democracy during peace. He certainly wasn't a communist, though he was somewhat a socialist (though inspired by Hinduism rather than by Marxism, so again, democratic socialist is most defining of him). However, Nehru was the historical leader of democratic India. Gandhi and Jinnah were also good contenders. Though Jinnah needs to lead Pakistan, he was a supported leader by Gandhi since Gandhi thought a Muslim leader could seal the rift between the Muslim minority and the Hindu majority. Gandhi himself also, though less likely, could have contended to being a leader as well (like how he is falsefully depicted as such in the Civilization series). Bose makes the most sense for Democratic India if India breaks out violently from Britain, while Nehru or Gandhi makes sense for leading India's peaceful breakout, and Jinnah pretty much requires India to be both democratic AND completely loyal to the Allied powers.
However I doubt this is happening, so if Bose has to be for one of the two, I'd say the Fascists. Even though he only held the "authoritarian" part of the Fascist ideology, and not even in a permanent manner, he was DEFINITELY NOT a Communist. This decision is literally "He is a fascist because we know he wasn't a communist, and there are no openings for anything else soooooooo yeah".