They are pretty slow, I've tamed two at a low level on SE and the Island. Find a steep cliff or a high rock, and shoot the shite out of it. They won't go around in circles they'll just put their head in the rock until they turn and run off because of the torpor. Keep shooting until it's down and you are good. Make sure you check if there are any other enemies nearby. That easy, no traps, no building, just a steep rock.
I encountered a level 15 one two days ago, tried taming and ended up killing it. Just found a level 14 female and want to tame it but don't wanna kill it. I have around 21 tranquilizer arrows, 60 stone arrows and I can make the 4 foundations and walls trap. I want to know when does it run away? I mean, how much can I hit it before it tries to flee? It has 1300 of life
I recommend using a scorpion to tame it, pump all levels into health on the scorpion. Then just attack the Rex but with 10 to 20 seconds in between hits, DO NOT pump anything into dm. Also this is what I use to tame literally everything, and it doesn’t even cost anything. Pls put this up in chat for everyone to go “oh that’s not a bad idea” 👌😄👍