What language did aryans speak when they migrated to india?

When Aryans invaded India, Circa 1500 B. C. they did not come with a language which had any known name. They would have spoken a kind of minor language with no script or literature. They found Tamil, a highly developed language, spoken throughout the Indian sub-continent up to Baluchistan in the Himalayas. Tamil was found to be a language with 3 independent fields of ‘Iyal (Prose), Isai (Music) and Natakam (Drama) ’. Dr. Vincent Smith, a noted British historian, in his book on Early Indian History, refers to the contribution of Tamil especially words borrowed by Aryans into their language. Tamil had developed advanced grammar, as proved by the great grammar treatise ‘Tholkappiam’. Later, Panini’s Sanskrit grammar, has borrowed heavily from ‘Tholokappiam’. For e. g. ‘Sandhi rules’ of sentence construction.

There is no evidence of the Aryans having spoken any kind of significant language as they entered India. If they had spoken a significant language, the remnants of it should be spoken now in the area from where Aryans migrated.