Hunas were a tribe close to Himalayas that, because of limited interaction with Indian kingdoms, were mentioned in the epic Mahabharata. They belonged to the Xinjiang province of China, east of Jammu-Kashmir. However, they were nomadic people who changed their settlements from time to time.
Among the tribes of the north are the Mlecchas, and the Kruras, the Yavanas, the Chinas, the Kambojas, the Darunas, and many Mleccha tribes; the Sukritvahas, the Kulatthas, the Hunas, and the Parasikas; the Ramanas, and the Dasamalikas. (6,9).
According to Dr V. A. Smith, this verse of Mahabharata is reminiscent of the period (4th/5th century AD) when the Hunas first came into contact with the Sassanians dynasty of Persia (See: Early History of India, p 339, Dr V. A. Smith; See also Early Empire of Central Asia, W. M. McGovern).
Mahabharata links the origin of Hunas with sage Vasishta. Viswamitra, a king in the Ikshwaku clan, attacked the cow of Vasishta. Then many armies emerged for the protection of that cow and they attacked the armies of Viswamitra. Cow symbolizes land, in ancient Indian scriptures. Thus this war was fought with the tribes allied with Vasishta for their own land. Other tribes that were mentioned along with the Hunas in this incident were Sakas, Yavanas, Savaras, Savaras, Paundras and Kiratas, and the barbarous tribes of Khasas, Chivukas, Pulindas, Chinas and numerous other Mlechchhas. (1,177)