He despawns upon completion of the stone of entry portion is complete and respawns 1 game day (2 hours) later to prevent the raid event for BiC #1 from being completed immediately after the group portion.
As you enter Qinimi, head right along the wall. You'll come to two sets of buildings, one set of four smaller buildings and a set of one large building and two smaller ones flanking it. The Councilman is located in the westmost one, nearest the Ferubi ZI, in the back corner, along with a noc darklurch. Beware of the wandering kyv's which don't seem to see invis and the urkun bloodhound which does.