To be judged by 12 is to go to court and to be judged by a 12 man jury, which all court trials have.
To be carried by 6 is to be dead. It is common for 6 people to carry a coffin (3 on each side) to and from the hearse.
In total the phrase "I'd rather be judged by 12, than carried by 6" means that the person would rather kill someone and go to prison than to, themself, be killed and have to be buried.
A Juggernut occurs when someone abstains from ejaculating for a long period of time(both sex and masturbation) until they finally relieve themselves in the most unstoppable and largest nut of their life.
"It had been a month since i last nutted, but I fucked that girl trixie last night and gave her the Juggernut... She was covered from head to toe"
The manliest state of being. Basically being able to do any of the following: chop down trees with your penis, eat rocks for breakfast and shit out gunpowder, headbutt your front door open, causing it to splinter into pieces, jump off a cliff and break your fall with your face, wrestle sharks, kill a bear with your bare hands, etc.
The absolute highest level of awesomeness that one being or thing may achieve, it is a term that cannot be beaten by saying "more juggernawesome" because the only thing cooler is Chuck Norris