iPhone Dev Team has just released Redsn0w 0.9.15b1 that supports tethered jailbreak for iOS 6. Earlier we had to install Cydia manually by pointing it to the firmware file but not anymore.
As we told you that currently the new Redsn0w only provides tethered jailbreak. Its compatible with devices that are Limera1n exploitable that includes iPhone 4, iPhone 3GS and iPod Touch 4G. Any other devices other than the mentioned ones are not supported.
How To Jailbreak iOS 6 Tethered With Redsn0w 0.9.15b1
STEP 1: Download Redsn0w. If you are on Windows, then right click and “Run as Administrator” and if you are on OS X Mountain Lion, control click to open it. Then click on “Jailbreak”.
STEP 2: Put your iOS device off and put it into DFU mode.
STEP 3: Make sure “Install Cydia” is checked and click Next.
STEP 4: Once the process is completed, it will show you the following screen.
STEP 5: Once your iOS device is booted up, you need to make it go through a tethered boot. Click back on Redsn0w and click on “Just Boot” and put your device in DFU mode again.
STEP 6: It will go through a couple of screen and in last it will show you a ‘Done’ message. After your device is booted up, you will see Cydia installed in it.