The predominant religion in India before Islam began to expand there was Hinduism. India is often described as having a diversity of religious believes and many different religious practices. The fact is that India has no state religion because they are a secular state, and freedom of religion is a constitutional right. That is an important factor for India to have such a diversified number of religions.
The Indian subcontinent which is composed of India, Pakistan and Bangladesh is considered to has been the birthplace for Hinduism, Buddhism, Sikhism and Jainism which are four of the world´s major religions. Thanks to the constitutional freedom of religion in India we can see the practice of Christianity, Zoroastrianism, Judaism among others.
A census conducted in 2011 showed that 78.9% of India´s population practices Hinduism, while 14% approximately practices Islam. Today, there are more than 500 million Muslims in the Indian subcontinent. It was very natural for Arabs to begin bringing their Islam to India when they started exploring the continent looking for spices and other products. The expansion of these commercial activities put India in direct contact with the new religions.