I'm not sure what you mean by "u9 dota". Could you please provide more context or clarify your question? Are you referring to:

1. A specific player in Dota 2 with the username "u9"?

2. A version or update of Dota 2 (like patch 6.89)?

3. An abbreviation or acronym I'm not familiar with?

4. Something else entirely?

If you can give me more information, I'll be better able to help you with your query about Dota 2.