Actually it really is about 90% Hindu. Its a country of over a Billion people. Around 100,000,000 people are muslim. Give or take a few million, most of the rest are Hindu, and there is a small christian/jewish/buddhist segment. Though small by percentage, is actually huge numbers.
Today has a Moslem population of 140Million - second largest in the world. Probably the most moderate too.
"...
Population (1999 est.): one billion; urban 32%. Annual growth rate: 1.8%. Density: 311/sq. km. Ethnic groups: Indo-Aryan 72%, Dravidian 25%, Mongoloid 2%, others. Religions: Hindu 81.3%, Muslim 12%, Christian 2.3%, Sikh 1.9%, other groups including Buddhist, Jain, Parsi 2.5%.
...."
www.state.gov