Nope. There is no jailbreak for A5+ processors with iOS 6.1.3. And, at this point in time, Apple has prevented users from downgrading to iOS 6.1.2. Maybe someone will come up with something when iOS 7 is released http://www.latinospost.com/articles/18237/20130503/ios-7-rumors-release-date-still-time-preview-wwdc.htm