Would India have been much different if the British had'nt colonised it?
I totally agree with Toukyou that an India with out colonialism would have ended up probably being several or many largely linguistically identifiable states. The Maratha Confederation may well have dominated but there were other strong Indian contenders such as Mysore during the 18th Century. However, the question was would India be different if the British had not colonised it? To answer this question it is much more likely had the British not stepped in one of the other European powers most probably the Dutch or the French would have. Following the decline of the Mughal Empire there was a vacuum and while Mysore and the Maratha's tried to fill it the relative military weakness but significant wealth of India would have attracted the attentions of one of the other European powers.
India wouldn't have been a country. It's current boundaries are based on British India - with the exception of the Portuguese/French enclaves and the Pakistan succession. India wasn't really a concept before the British.
India would resemble something similar to Europe probably. If we presume that ethnolingustic nationalism took priority over empires, we would probably start to see some sort of ‘EU' including Lanka, Nepal and Bhutan.
India would also probably be ideologically Hindu, similar to the Buddhist countries in East Asia that kept that ideological stance with them.