Council of 9 (High Council/The White Council/Council of Light)

Usually have odd numbers of Elders sitting on the council, but it can be even depending on current events and situation.  Can have indeterminate amount of Elders, has been 11 in the past, now have 9.  May be 10 in the future.  Usually have odd amount of members to make for easy voting.

Council of 5 (Low Council/The Black Council/Council of Darkness)

Usually have odd numbers of Elders sitting on the council seat, never have even number of members, always have less than 6 members to control situation.

The Grey Council

Have indeterminate amount of members, usually have the most amount of seats for Elders.  They are the neutrals or undecided.

Council of 3

The council in support of the sitting member in the Council of 13

Council of 13

The ruling council, has representative of each race as sitting member in the Known Universe, they discuss what needs to be done, and what will happen for their own colonies and planets.

There may be more councils, I do not know about, but these are some of the major ones.