How did European imperialism differ in India, China, and Southeast Asia?

it happened during the division of Asia.

In India the colonialism was conducted by the East India Company, a commercial organisation, until after the First War of Independence/Indian Mutiny, when the British Govermnment took over.

In China there was never direct control of large swathes of countryside. The colonial powers insisted on and enforced trading concessions, but, apart from limited areas for their factories (trading posts), did not exert direct control.

In Southeast Asia most colonial territories were fully annexed and governed by the central government of the colonial power.

Very broad brush summary.