Radek Polomik is originally from Prague, Czech Republic, but he now lives in Seattle, Washington. He tried out before for Season 10, and made it in front of the judges, where he was buzzed by all four and eliminated. 
Radek Polomik's audition in Episode 1201 consisted of performing his "Happy Jellyfish Dance." Howie Mandel, Mel B, Heidi Klum, and Simon Cowell all buzzed the act. Although Simon voted "Yes" (according to Radek on Facebook), the other three judges voted "No," eliminating Radek from the competition.
Radek auditioned in season 10 where he was eliminated in the audition round. However it was never televised