If you do not have SHSH Blobs, there is no software tool currently available that can bypass this requirement on the iPhone 4s.
Downgrading an iPhone 4s to iOS 5 is significantly more restricted than downgrading to iOS 6. While iOS 6.1.3 remains "signed" for the 4s via an OTA (Over-The-Air) update loophole, iOS 5 is not, making an untethered downgrade impossible without SHSH blobs . Downgrade Methods
If you do not have SHSH Blobs, there is no software tool currently available that can bypass this requirement on the iPhone 4s.
Downgrading an iPhone 4s to iOS 5 is significantly more restricted than downgrading to iOS 6. While iOS 6.1.3 remains "signed" for the 4s via an OTA (Over-The-Air) update loophole, iOS 5 is not, making an untethered downgrade impossible without SHSH blobs . Downgrade Methods downgrade iphone 4s to ios 5