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.
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.
The Ark Mobile Single Player. Can be tamed using an enclosure. Better than spending a few hours trying to KO and have it drown. Requires 12 or so Behemoth Gateways. Set up in a rectangle or circle. Lure titanosaur into enclosure. Place last gateway. Now using your Queztal blast it’s head with cannon. Move out of render, return and repeat til KO.