If you have a platform saddle for a quets then put cannons on it. Then aim for the head a fire.

You can actually knock a titanosaur out with a mek,take at least 30 cannon shell and if you are feeling adventurous,try a quetz or hover skiff with a cannon ps:don't use a ballista with boulders

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.

You smash it with a ballista and give it brain damage.
Force it to be your friend by putting a saddle on it.
Then it almost starves and you heal it.
Then you try to take on a giga, It dies to it.

You can use the canon of the mek to tame it its a lot more easier