Its a ballot for the tickets with local residents hopefully getting preference, have to say do not know much about Rizzle Kicks but I guess the younger members of the community will know them, not sure on what the capacity will be in front of the stage but supposedly health and safety comes into it as to how many people are allowed in that area.
Ticketmaster usually charge a administration fee so watch for that.
Kyle has answered some of the questions in the above post.