At time of writing, iOS 6.1.3 was the latest iOS version, but there was no jailbreak available yet. If you already updated your device to 6.1.3, you can't jailbreak with evasi0n. You will have to wait until a jailbreak is available, and remember not to upgrade too before checking the jailbreak availability next time!
While the evasi0n team waits for the iOS 7 release to make a new jailbreak available, there is a way to downgrade iOS devices running 6.1.3 to iOS 6.1.2 and benefit from jailbreak.
The table below gives a summary of jailbreaks available for iOS initial versions:
|Device||iOS initial version||iOS latest version||Jailbreak|
|iPhone 4 (GSM)||4.0||6.1.2||evasi0n|
|iPhone 4 (CDMA)||4.2.5||6.1.2||evasi0n|
|iPod Touch (1st Gen)||1.1||3.1.3||Redsn0w|
|iPod Touch (2nd Gen)||2.1.1||4.2.1||Redsn0w|
|iPod Touch (3rd Gen)||3.1.1||5.1.1||Absinthe|
|iPod Touch (4th Gen)||4.1||6.1.2||evasi0n|
|iPod Touch (5th Gen)||6.0||6.1.2||evasi0n|
|iPad (3rd Gen)||5.1||6.1.2||evasi0n|
|iPad (4th Gen)||4.3||6.1.2||evasi0n|