Dravidians – Speakers of Dravidian branch of languages.
Indo-Aryans – Speakers of Indo-Iranian languages.
Indo-Europeans – Speakers of Indo-European languages. This includes Indo-Aryans.
In Indian-subcontinent including India, if one speaks Indo-Aryan language it may not mean, he is a descendant of Indo-Aryan people. It could be that the influence of Indo-Aryan language had overcome Dravidian language in that area. Whereas this was not possible in southern India because of restricted migration of Indo-Aryan speakers and high degree of movement by Dravidian people.
Revelations of the Other World 