Just knock it out, walk away and let it starve, don't waste narcotics or berries. Once it wakes up knock it out again, usually one arrow to the head. Begin taming from there. Bola is useful if you have trouble hitting its head.
Are you a new Ark player? A Tipp for you. He is fast... faster than you. The best way is craft Bola and Bola the Parasaur. Knock out and feed it with Berries. Dont miss nacoberries... Good you tamed it! Craft a Parasaur saddle and ride it! Good luck. (pls vote 🔼 to beginners see this)