Central District, 11th Avenue is a stage in Tekken 6's Scenario Campaign mode. Bob is fought here. Clearing this stage and defeating Bob will unlock him in Scenario Campaign and Arena mode. This stage is optional, unless the player wants to unlock Bob.
"This town has an astonishingly high crime rate, but we were able to find one man with a strong sense of justice. He leads a group of vigilantes for the purpose of protecting the city's inhabitants, and so mistook Lars and I for criminals. He eventually led us to the outskirts of the city, and told us that we could find safe haven in a tourist city just ahead".