Witzel:
"The prefixes of the RV substrate are, however, close to, an in part even identical with those of Proto-Munda; taking my clue from Kuiper (1962: 51,102; cf. now Zide MT II: 96), I will therefore call this substrate language Para-Munda for the time being ...
Para-Munda (viz. directly from Austro-Asiatic) ... Of special interest for the RV substrate are the prefixes ka-, ki-, kŻı-, ku-, ke-, which relate to persons and animals (Pinnow 1959: 11; cf. p. 265 §341a) and which can be compared, in the rest of Austro-Asiatic, to the ‘article’ of Khasi"
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
Witzel divides the Rg Ved into three parts - early, middle, late - and finds no Dravidian in the early, but does find the AA type. He also places the early part of the Rg in the modern Punjab area, which then conflicts with the known geographical extent of the AA languages. If Witzel is to be believed, AA potentially extended from Sumer to the south-east of China.