Six Council Members total. The number of Council members was originally outlined in the By-Laws. I can’t remember if it’s also listed in the Constitution. Let me see if I can get a current Council member to chime in here. It’s a great question so thanks for asking it.
The Council mix isn’t based on regions specifically. Region should be a part of the mix, yes, but you don’t ever want one region dominating the Council.
IMHO, the new Council mix should would be most effective if balanced by business acumen, diverse expertise/skill set (ex. meaning representatives that include developers, entrepreneurs, legal, government), diverse gender mix (we have an all male Council now), diverse/balanced regional mix (Asia, EU, North America, LATAM, etc.), strong communication skills, temperament/personality (something like doing a Myers-Briggs Type Indicator test might be helpful), and having a track record of working well across different cultures + groups.
Also, there’s additional support with Directors, past ExCo, Advisors, Core Devs, and Legal. So the Council gets input from a wide range of areas.
Edit: Above I’m referring to the current 6 open Council positions (and not including the 4 ExCo positions in this.)