Phone [Q] HTC One Rooting Problem

Please Help! I have a HTC One X At&t unlocked phone with lot of issues. I decided to install custom ROM on this phone. I am a newbie in the world of rooting, flashing etc. I follow some directions and I was able to unlock my boot loader then installed twrpv.2.6. I tried to flash one custom rom that I found in web, during flashing twrp give me a message "Your phone is not rooted. You want to flash SuperSu. When I confirm and reboot the system, phone stuck in htc logo screen with white back ground. I guess my phone lacking super user permission. Is there any way I can fix my phone?

I tried to manually put su and other files into this phone but its lacking following directories

system\bin\su
system\xbin
data\local\temp