No, this means you will need a mix of tier2/3 heroic and a few raid pieces from tier1 raid to meet the requirement. Full tier2/3 heroic will likely not give you enough to put you over the resolve number for tier2 raid bosses. That doesnt mean you can't kill them even if you are a few resolve short its not a hard requirement it just gets a little more difficult.
City of Mist zones are considered tier2 or higher.
T2 Heroic has resolve at 190(ish) but that is subject to change based on difficulty feedback.
It will need to be discovered.