I don't know anything on the topic, I assume even if most people consider themselves han today atleast in China's early history there would be a lot of distinct tribes. How was their relationship with the empire? Were they autonomous vassals largely or were they assimilated quick by the central bureaucracy?
More can of course be said, particularly regarding earlier periods in Chinese history, but I discuss indigenous matters during the Qing era in these answers:
Similar question about Europe and Asia, with an answer that primarily talks about southern China:
Extremely fascinating answer about interactions between the Ming Dynasty and Southeast Asia. Most pertinent part would be the section about Yunnan since it actually bordered the Ming.
https://www.reddit.com/r/AskHistorians/comments/7pezki/was_chinas_influence_on_southeast_asia_ever/
Summary of various steppe empires of Asia:
Books about steppe nomad history:
edit: here's another interesting link about how mongols were integrated after the fall of the Yuan