There are multiple places to find them in the center map but in the original map and scorched earth.in sorched earth you head to the center of the map or to where the giant spikes are you can knock them out any way that you can but I suggest to bring as many tranq darts as you can or tranq arrows .and they spawn just about anywhere near the red or blue obelisk in the normal major in the center around red wood
I would think these were gonna be harder to tame but they’re actually not that hard, my stamina and movement speed is pretty high I’d say around 200 or higher but I didn’t need a trap or any of that, all I used was tranq arrows, u shoot it once then run away for a little bit turn around quick shoot it again then run away again and shoot it again and repeat, if it starts running it means it’s almost knocked out just chase after it and keep shooting and feed it meat!
I recently tamed a Rex and it was not that hard at all. So if the Rex u are looking for is level 1-15, Then you only need like 30 tranquil arrows. Just find a hill bigger than the Rex and can’t be climed by one, Then get its attention and start shooting. Just don’t let anything eat it when it gets knocked.
If you use the bear trap strategy which is if you lead it into a Dino gateway that is shaped in a triangle and with a bear trap in the middle (Large Beartrap) and when it is stuck you must put a dinogate behind it to trap it and then knock out.