One Final Counsel is a brief main quest in Assassin’s Creed Mirage.
Your objective is to report to Roshan after finding out who Qabiha is.
Here’s a walkthrough and guide of One Final Counsel in AC Mirage.
Report to Roshan
Go to Roshan who is waiting at the location marked in the map below.
You’ll see her on the rooftop. Talk to her.
After talking to Roshan, Nehal appears.
The aim now is to assassinate Qabiha and this quest ends here.