if you're wanting to buy the tickets, আপনি can't. Tickets have been sold out for maybe a month. But, আপনি can prob check ebay. Maybe some people are selling them for over priced there if আপনি really want to go. But do আপনি really want to risk your hearing?
There will be so many fangirls there. The room fits a certain amount of people, but I'm sure the fangirls will pack in. Plus they'll be screaming, and if আপনি don't get a good seat, আপনি won't be able to hear anything. If আপনি get annoyed easily, especially with the fangirls, I suggest just watch a live streaming video if they have them online.