Download UltraSnow 1.2.8, support Unlock iPhone 3GS running iOS 6.1
If you haven't untethered jailbreak your iOS 6.x using Evasi0n yet I suggest you to do so because Evad3rs just released it today. And if you did and looking for a tool or tweak on Cydia that can help you Unlock your iPhone running iOS 6.1 then you should install UltraSnow v1.2.8. You have 2 choices, just choose one.
1. Unthered Jailbreak your iOS 6.1 using Evasi0n
2. You have a iPhone 3GS BB 5.16.07,04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00 & BB 01.59.00 for iPhone 4
* How to Unlock an iPhone 3GS running iOS 6.x (Choice #1)
Step 1: Download Ultrasnow 1.2.8 here
Step 2: Copy the .deb file to the following file of your iPhone Private/var/ root/ Media/Cydia/autoinstall/
Step 3: Once you did it just reboot your iPhone 3GS and you will be good to go. Good luck!
* How to Unlock an iPhone 3GS running iOS 6.1 (Choice #2)
Step 1: Go to Cydia and add the following source: cydia.heaveniphone.com
Step 2: Once the source is added, tap on search and type in Ultrasnow fixer for iOS 6.x or just Ultrasnow fixer and you will see it.
Step 3: Tap on Ultrasnow fixer for iOS 6.x and install it. Once you done so. Reboot your iDevice.
Step 4: Congratulation! You just unlock your iPhone 3GS running iOS 6.x