The High Council, sometimes called the Supreme Council, also referred to as High Council of Time Lords, was the governing body of the Time Lords on Gallifrey.
The Council consisted of Cardinals representing the colleges of Gallifrey, the most prominent being the Prydonians.(DW: The Deadly Assassin)
The Inner Council consisted of the Lord or Lady President, the Lord or Lady Chancellor, and the Castellan. (DW: The Deadly Assassin)
Other offices affiliated with the council included the offices of the Gold Usher (DW: The Deadly Assassin), the Surgeon General (BFG: source?) and the Inquisitor. (DW: The Trial of a Time Lord)