Apple registered developers who have successfully installed iOS 6 beta 3 on their iPhone 4, iPhone 3GS or iPod touch 4G, can use latest RedSn0w 0.9.13dev3 for a tethered jailbreak of iOS 6 beta 3 if they required it.
iOS 6 is integrated with 200+ new features, and iOS 6 beta 3 is not a final product yet, so you do not need to worry if some of it features, apps or Cydia are not doing well after getting jailbreaked.
Warning: Users who rely on UltraSn0w unlock must stay away from iOS 6 beta.
Redsn0w 0.9.13dev 3 for Windows(run in Administrator Mode)
Redsn0w 0.9.13dev 3 for Mac