India could denote a civilization. Just like western civilization denotes Western European culture. But a civilization does not entail a nation. Just like Western Europe has never been a nation.
Without the British unified India. India would not exist as a nation today.
Wrong!
Before British conquered India, there was about a hundred years turmoil, where smaller Indian Kingdoms were fighting for power to become master's of entire Indian empire.(which is why British were able to conquer India in the first place). But before that Indian empire was united for centuries under one dynasty or the other.
So if British hadn't united the smaller fighting Indian kingdoms,eventually another Indian kingdom, would have united the country under a single rule. For that is law nature.
So India would still have existed as nation today, perhaps with different geographical map.