It depends on your budget.

Companies like Nielsen or other international market research companies had offices in these cities and they offered professional research services.

However, many successful teams in the region would build their own research projects in-house. If you are in a budget, you can try free tools like Statista to get a sense of the publishing market. If you want to dive deeper, you can come across with a bunch of Chinese content (e.g. http://ipubl.com/site/gjcb/bg/info/2017/840.html ), which you may need some help; for user interview services, that is not as popular as the west, it may be better if you just hire some part-time helpers to conduct interviews for you.

Marketing channels are highly diverse, there are lots of "agencies" in the region claiming they offer "all-in-one" packages, but they are more focused on executions/ creativity inputs instead of the actual outcome, which should be aware of.