This is not another web site, which is said can be jailbreak Apple TV3.
In these days from so many websites publishing through their web sites, they have software, and they can be jailbreak Apple TV3. However, base of my knowledge, still there is not any tool or software to jailbreak it.
Accordingly my knowledge Snow3rd is the first jailbreak tool for Apple TV3 but still on Beta version. If you wish to jailbreak through Snow3rd, but it can use up to ios 5.1.2.
With these difficulties, there is a good alternative for Apple TV3 jailbreak. As you know jailbreak main goal is removing Apple limitation and install third party application to the device. In the Apple device family, Apple TV is a totally different device. Why I say like this, Apple inc- offering Apple store to all devices except Apple TV.
When you want to get any third part application to Apple TV, the one and only way is a jailbreak. The plex media server is the one of the third party media application, which is can install after jailbreak. I think you may remember, in this content, I highlight alternative for Apple TV 3 jailbreaks. It is plexconnect .
It is not requiring jailbreak, with a couple of TV setting change you can install it.
plexconnect download 