Dalek Council

The Dalek Council was the governing body of the Daleks on Skaro. They convened in chambers on the fourth Level of the City. They were presumably destroyed when their power was drained away. (TV: The Daleks) When the Daleks tries to win the Great War, the Dalek Emperor and the Supreme Council determined that the Dalek Factor had to be researched so they could recondition humans with Dalek mentality throughout their history, potentially preventing the wars from ever happening. A Red Dalek acted as an emissary for the Council, overlooking the experiment being carried out by the blackmailed Second Doctor on Earth in 1866. (PROSE: The Evil of the Daleks)

Some time after the Daleks recovered from the resulting Dalek Civil War, (TV: The Evil of the Daleks), a Dalek Supreme with a gold and black casing was identified as "one of the Supreme Council". (TV: Planet of the Daleks)

In an alternate timeline where the New Dalek Paradigm conquered Earth in 1963, the Supreme Council Chambers were located in Kaalann. (GAME: City of the Daleks)

In a later stage of the New Dalek Paradigm's history, the Dalek Council appeared to have been replaced by the Parliament of the Daleks, led by the Dalek Prime Minister, then the Supreme Dalek below him, along with several Strategist Daleks, hundreds of Officer class Drone Daleks, and Thousands of drones of a design resembling those from the Last Great Time War. (TV: Asylum of the Daleks)

Behind the scenes
According to REF: Doctor Who: The Dalek Handbook, a non-narrative source, the Daleks established a Council during their recovery after the Great Civil War on Skaro.

According to REF: Doctor Who: Aliens and Enemies, a non-narrative source, the Dalek Emperor's Personal Guard made up the "High Council of Daleks", of which the Dalek Supreme was also a member.