The Inner Council consisted of the Lord or Lady President, the Lord or Lady Chancellor, and the Castellan. (TV: The Deadly Assassin, The Five Doctors)
If the other two members of the Inner Council were in agreement they could overrule the Lord President, an event which happened, when, against President Borusa's wishes the Castellan and Chancellor Flavia voted to summon the Tremas Master to Gallifrey. (TV: The Five Doctors)