To immobilize/stop it from moving,using a bola is your best bet. For knocking out,I suggest using tranq arrows with a basic bow. There is less chance of it dieing that way. I'm a higher level in game,so I built a tame area with behemoth gates for dropping in wild tames with a quetz. This makes it easier to knockout and tame without the added worry of attacks.
There’s sooo many taming and ko tips for these guys? But none of them are actually taking tips! The only thing about knocking them out that I’ve seen is just shoot it with tranqs. Bruh... u shoot it one and it runs away from u. There’s like a 2% chance that you’ll hit it a second time. :/