According to the anime data leaked, the council members' names are:
Mid-aged man with round sunglasses and upturned moustache: Reiji
Old woman with silver hair and huge golden earrings: Noula
Mid-aged man with gray hair and helmet on left shoulder: Babaraki
Old witch-like woman with gray hair and pigtail: Lowen
Mid-aged man with brown hair and an eyepatch on right eye: Shido
Not to mention Org and Gran Doma. The rest two man are unnamed so far.
Edit: the long-faced frogman with Nadal is called Serena.