you have to beat him into submission (I believe its 10% down in health) but you need the Rhesusbeast blood vial in order to do so. You need to consume it, did you do that before attacking him?

yes i did that and beat him 4 times and nothing happen i don't know what's wrong with him

It might be glitched then, I'm not sure why that would happened other than maybe because the mod is way out of date and some things are breaking (like the alpha sacros and scourages losing their texture skins) . I tamed one on my island server without a problem but that was like last year this time, I will try to tame one myself and see if i can help you any further. Did you try dotame?

oki thx man for helping