Indonesia has the most Muslims in the world, though India has more than Pakistan (10% of a billion+ people is still a lot). Pakistan has never forgotten that India broke them in half by sending troops to help Bangladesh (East Pakistan) leave “West Pakistan”. They did the same thing with the Sihks and in Sri Lanka, and Indira Ghandi and her son Rajiv (no relation to the Mahatma) died for it.
As long as Americans think of India as a country, they will never understand it - though not geographically, it is a continent.
Pakistan conveniently forgets that the West Pakistanis (Punjabis, Pathans, Sindhis -- all generally Urdu speaking, fairer Aryans) persecuted and discriminated against the East Pakistanis (Bengli speakers, darker Aryans) -- when the East Pakistanis won the majority in parliament in 1970, the West Pakistanis did not allow them and kicked them out (Bhutto).
Then the West Pakistanis committed genocide there -- killing and raping and wounding nearly a million+ Bengalis. India had 10 million refugees come streaming over her borders
India had no choice but to help the Bangladeshis
what makes the Pakistanis so angry is that India smashed the Pakistani forces so easily -- in a few days the war was over and the Pakistani myth that they were a warrior race as opposed to the "cowardly Indians" was shown to be a lie. They never recovered from this.
What was even funnier was that the Field Marshal in charge of the Indian action was a Zoroastrian, he had an Indian Jew (Jews have lived in India for 2000+ years), Sikh, Christian AND Moslem senior officers..
Correct again -- india has 800 languages and dialects from 7 different language super-families (Aryan, Dravidian, Munda, Tai-Burmese, Tibetan, Mongoloid, Jarawaetc.)
By race, 70% of its population is Aryan, 25% Dravidian, 5% Mongoloid, Australoid, etc.
By religion it has (approximately -- I can't remember the actual numbers) 900 million Hindus, 150 million Moslems, 40 million Christians, 20 million Sikhs, 20 million Jains, 5 million Buddhists, 70 thousand Parsis/Zoroastrians, 5 thousand Jews (most migrated to Israel -- but India was the only country Jews were not persecuted)
It is far more diverse than the European Union -- it is not a nation-state as say England, but a federation of multiple states, ethnicities, religions etc. -- a continent as you say (in fact, just as Europe is called a continent separating it from Asia because of the Urals, technically India too is a continent, separate from Asia)