"Hokan" is a linguistic classification, grouping together a number of language families in North and South America. There is no single language called "Hokan", and there's no single greeting that would be used across all languages in the Hokan language family.
To know how to say "hi" in a specific language, you need to specify which language within the Hokan family you are interested in. For example, some languages within the Hokan family include:
* Chumash (California)
* Yuman (California, Arizona)
* Karuk (California)
* Washo (California, Nevada)
* Pomo (California)
If you can tell me which specific Hokan language you'd like to learn, I can help you find the right greeting.