You hit it with cannons on a quetzal. Go for it’s head. It’s torpor won’t drain either so take your time. They can’t eat just stuff a platform saddle on the titan once KO’ed. You use daedons to heal it when it’s food level is low.
On mobile single player I used about 12 behemoth gateways to make a large pen. Lure titan into pen, place last gateway and tamed with Quetzel/cannon technique. Just go past render distance after each shot and come back and repeat. This was tedious but better than it drowning when it flees.