Im on mobile so i do not know if it will work on other platform too

-Easy exp if you ask me, i'm lv 79 and had killed 2 so far, they give hell lot of prime meats and give about 5000 exps

-Simply lure it into the ocean,deep enough to cover it entire body,next mount a dino that deal ton of damage because this boi is amored,lastly swim above it body and attack all you want as long as you above it body it wont be able to hit you

-Make sure your dino have good amor and health to suvive a couple of hit from the titan since sometime the titan will try to go back on shore, if this happened you could either use you dino and attack the titan then go back to the ocean and contineus the beating or use a bow or crossbow to shot it (gun wont work since you are IN THE WATER)and contineus the beating

-When it at about 70000 health left lure the titan up so it can get some air then lead it back to the ocean and contineus the beating until it died, when it at low health it will run from you(YES it will run from you)which it will more likely swim farther into the ocean and get itself downed before you could even kill it

-killing the titan this way is time-consuming(took me about 30 minutes)but its the cheapest way i found so enjoy

-Some of you reading this may think im crazy or stupid or

im just lying but trust me, try it for yourself, just in case if you messed up remember to back up your save file