Can anyone please suggest drama as same as THE UNTAMED!!!! 

It's amazing eeh? I totally agree haha hm...sadly i havent seen anything like it. I guess the closest a drama has gotten (that i know of) is Warrior baek dong soo. The bromance is so cute however Wareior baek dong soo is a korean drama and it is not based on any BL novel. But do check it out :)

Not a historical drama, but if you want bromance, try Guardian starring Zhu Yi Long and Bai Yu.

agree on Guardian for bromance

If you're looking for xianxia (cultivation and stuff), how about Ever Night, The Journey of Flowers, and Noble Aspirations?

As for bromance, I'm not too good with this but Nirvana in Fire has some good bromance there, if you haven't already watched it.