An ugly truth, one that must never be spoken too loudly, is that most of the people designated "lower castes" by the "upper caste" Hindus, and others designated "tribals" (adivasis), follow a variety of ancient pagan personal "religions" (belief systems) that are "Hindu" in name only. They don't actually consider themselves "Brahminical Hindus", and are forced to identify (by the "Brahminical Hindus") as Hindu because that's the only choice available to them, in census forms, etc.