Question

y is India only India, but America, the America

Answer 1

There is little method and quite a bit of madness in the way the definite article is used in English. But some rules can be deduced from particular examples. However on the whole, the only rule about such things is that standard usage should be followed.

The definite article "the" is used with a geographic name if the name has a separate meaning (apart from being a name.)  E.g. the Punjab (Punj-Ab = five waters), the Deccan (Dakshin= South), the Coromandel (Chola-mandalam= circle of the Cholas), etc. in India. Also, the Netherlands (=low countries), the  Hague (=the wood or the hedge), the Sahel(=the coast), the Sudan (= the blacks in Arabic), the Prairies=the grasslands, the Pampas (=plains in Spanish). More simply, the Midlands, the Midwest etc.

Among countries, there are some whose names do have names independently of being used as a name for the country. With some of these (USA, UK, Vatican City State, USSR, Philippines, Netherlands, etc.) it is customary to use "the". 
 
We may note here that in some languages e.g. French the definite article is mandatory with all country names. L'Inde, Les Etats Unis.

Answer 2

Hi buddy
Here is ur answer
India is only India because
*in India there are different types of religion, caste, creed etc people live.
*here there is no comparison b/w each other.
*here different type of people exist


America is America itself because
*here there is no unity


Hope it helps u
Bye