Hara-Huna was an ancient Chinese kingdom and inhabited by the Hara Hunas tribe close to the Himalayas who had limited interaction with the Indian kingdoms, thus they were identified in the epic Mahabharata.
They lived in the Xinjiang province of China, east of Kashmir. However they were nomadic people who changed their settlements time to time.
The Pandava hero Nakula visited this place during his western military campaign for collecting tribute for Yudhishthira's Rajasuya sacrifice. This could be a branch of Hara-Hunas migrated to the west of Ancient India.
References
Hara Huna Kingdom Wikipedia(Text) CC BY-SA