Apple released iOS 6.1.6 firmware update for iPhone 3GS and iPod touch 4G along with iOS 7.0.6 which resolves the SSL connection verification issue.
p0sixspwn has updated his jailbreak tool to support iOS 6.1.6 to perform a tethered jailbreak using Redsn0w. After performing tethered jailbreak you will be required to install the latest version of p0sixspwn package v1.4-1 from Cydia in and convert tethered jailbreak to an untethered.
Guide to jailbreak iPhone 3GS and iPod touch 4G on iOS 6.1.6 using Redsn0w
Download Redsn0w 0.9.15b3 for Windows and Mac –
Download iOS 6.1.6 for iPhone, iPad & iPod Touch.
Launch Redsn0w by double clicking on the icon. Windows users are required to run Redsn0w in Administrator mode.
After launching Redsn0w, click on Jailbreak, select Cydia and then enter into DFU mode.
3. Put your device in ‘DFU Mode’.
* Hold down Power (corner) button for 5 seconds.
* Without releasing the Power button, also hold down the Home (bottom center) button along with the Power button for 10 seconds.
* Without releasing the home button, stop holding down the power button for up to 15 seconds.
When in DFU Mode Redsn0w will start Jailbreak process. Select option “install Cydia” and click on the “Next button” to continue Jailbreak process.
Reboot your iPhone or iPod now.
This is untethered jailbreak.
To boot tethered
To boot tethered your device you will have to Launch Redsn0w and then click on the “Extras” and then click on “Just Boot” option. This will put your device into DFU Mode and then it will boot into Jailbroken state.
How to install p0sixspwn 1.4-1
When you jailbreak your iPhone 3GS and iPod touch 4G ,launch Cydia to install p0sixspwn 1.4 package which will convert your tethered jailbreak into an untethered one.