Birth of Hindu religion:
There are different opinions regarding of the birth of Hindu religion. There is literally a tug of war between the scholars’ one in favour of Dravidian origin and other of Aryan origin. There is hardly any third opinion on that though a small section feels that it has originated from indigenous tribal of India. This is because no great man of this origin had ever tried to write or researched to claim that Hindu religion is born from their indigenous tribal faith.

First of all the word Hindu it self has root to non-aryan Kirata or Borok origin with Sindu or Chindi river through the Indus civilisation, is not at all the Indo-Aryan one. Secondly the theory of Hindu religions birth from indo-Aryan faith is null and void by the following facts. Let us look at the list of names of Gods which the Indo-Aryan people had brought when they invaded Indus civilisation. Rig-veda has all the names of god which the Indo-Aryan used to worship when they first came to India. Their faith and philosophy were based on these gods only. The rituals, procedure and hymn etc were detailed in the sacred text of Vedas. Some of the primary and powerful gods mentioned in the Rig-Vedas are Indra, Agni, Varun, Vrihaspati, Brahma, Arundhati, Soma, Vayu, Aswin, Rhitu, Marut, Rudra, Ribhus, Savitar, Brahmanspati. But in the present day Hindu religion none of the Vedic god is worshipped in India. The Brahma is the only one ha temple at Puskar in Rajasthan, and he too does not have any day fixed through out a year. There is no god of Aryan or Vedic origin in the list of Hindu Gods of modern India, other than doubtfully the Vishnu which is considered to be origin of Dravidian. On the contrary none of the Hindu gods of modern India is mentioned or had a place in Vedas. These facts clearly prove that the Hindu religion and its gods are neither born from Aryan faith nor derived from Vedic gods and philosophy.

http://tripurasociety.org/hindu.htm