Khasas were mentioned along with Chivukas and Pulindas and Chinas, Hunas, Pahlavas, Sakas, Yavanas, Savaras, Paundras, Kiratas, Kanchis, Dravidas, Sinhalas and Keralas.
At (8,8) the Gandharas, the Madrakas, the Matsyas, the Trigartas, the Tanganas, the Khasas, the Pancalas, the Videhas, the Kulindas, the Kasi-kosalas, the Suhmas, the Angas, the Nishadhas, the Pundras, the Kichakas, the Vatsas, the Kalingas, the Taralas, the Asmakas, and the Rishikas were mentioned to be vanquished by Karna.
Pullindas and Khasas were mentioned together at (12,150) The Mahabharata details the various gifts given to Yudhishthira by Indian Kings and neighboring states at the Coronation Ceremonial (Rajasuya yajna).
The Khasas, Tanganas, and others brought heaps of gold in dronas (jars) collected by gold-digging ants (which most likely refers to Tibetan miners), chamaras (yak's tail), and sweet honey extracted from the flowers growing on the Himavat as tribute.
(8,20) The Tusharas, the Yavanas, the Khasas, the Darvabhisaras, the Daradas, the Sakas, the Kamathas, the Ramathas, the Tanganas the Andhrakas, the Pulindas, the Kiratas of fierce prowess, the Mlecchas, the Mountaineers were mentioned as fighting for Duryodhana.