On a separate note, one “Kuruṅga” occurs as the name of a Turvāsava prince in the Rgveda. In light of Paurāņika memory of Turvāsu-s/Turvāsava settling to southeast of Madhyadeśa i.e. Near Rewa, MP & given the historic tribal presence in MP & JH, one may be tempted to infer that Ārya clans like the Turvāsu had perhaps mixed with the local non-Ārya population as they expanded from Madhyadeśa.
The origin of kuruNga is not as trivial as modern linguists think it to be. Different hypotheses connect it to words like koraNgu (monkey) from Dr or an Austrasiatic word for antelope/deer or a tribal ethnonym name (kuruMga community – an “AASI” enriched caste in Odisha).
yAska etymologizes it as kurun+ga = a king who went against the kuru-s. It appears in the maitrAyaNIya as kulaNga and taittirIya as kuluNga. Hence, my own suspicion is that it is an old loan word that entered IA before contact with Dr or AA.