As aforementioned, it only supports those running A4 or below, so the , iPhone 3GS and the 4th-gen are compatible. Any of your newer devices running A5, A5X, A6 or A6X will not work.
How-to for jailbreaking iOS 6.0.1:
2. Download iOS 6, and the new iOS 6.0.1 for your device. Update your device to iOS 6.0.1. [Download iOS 6.0.1 from here]
3. Run Redsn0w.
4. Click on Extras –> Select IPSW option and manually point it to the original iOS 6 (not iOS 6.0.1) file for the device you want to jailbreak. Once the file has been identified by the Redsn0w, hit theBack button to go back to the main screen of Redsn0w.
5. Click Jailbreak, then select Cydia and follow the instructions to pop your device into DFU mode. Once Redsn0w has worked its magic, select “Autoboot this device when it connects in DFU mode,” which will put your device into tethered mode.
That’s it, we are done!
As mentioned before, you’ll need to "boot tethered" every time you reboot or switch off your device, and you can do so by opening Redsn0w, navigating to Extras and then Just Boot.
Source: Redmond Pie