Indians are steeped in religion and spirituality, about which there is an abundance of written and oral knowledge. However, individuals lose touch with spirituality and religion, and seek the support this offers, thus seeking to be reminded. Eloquent individuals with a grasp of the subject and an ability to explain the un-manifest, attract listeners, and a growing number of these listeners proclaim the speaker as a teacher, a learned one, a guru. Much of what the speaker does is all but explain, consolidate and encapsulate other teachings and religions, and express them in modern (current) thought. The eager listener grasps out for a teacher, the guru, and soon, this guru heads the group, which becomes his following. Sometimes, his words spread across boundaries, attracting people from other lands. Some of the followers observe each and every word of the speaker, and unknowingly help develop a faith. A combination of a better teacher, a better organization and the right environment helps develop such organizations to become more well known, and eventually into a sect, and finally, a religion.  Then individuals returning to their homes/countries, conjure up an image that would be familiar to the local population, to present to them.

Indeed, if you think back and consider the above, it is easy to accept that many of the now established religions started this way. 

It is the fertility and welcoming of the Indian mind that allows the seed of age-old understanding and good sense to grow into a garden, nurturing it to its vivacious color and smell. This garden attracts others from within the land and from outside. Passage of time and nourishment provided by the land and people transforms this garden to a forest, eventually finding its own presence in the landscape of religion and spirituality in India, and the rest of the world.

You will come across reference to many such lesser known religions, who have their own leaders with their retreats or ashrams where they congregate and offer discourses. There are perhaps tens of thousands of such groups spread around the country.

Also, read about the Bishnois.