Is ultrasn0w capable of unlocking iOS 6.1.2?

I have a n iPhone which is currently jailbroken on ios5.1.1 will ultrasn0w be capable if I upgrade to ios 6.1.1 or 6.1.2?

If I were you I would wait. I have the 6.1.2 on 3GS and ultrasn0w is not currently doing its job. However, I'm still at the early stages of diagnosing the problem, so I could be wrong.

You can try it! It will work. If it won't work. You can save shsh blobs of ios 5.1.1 and then downgrade and unlock it again with ultrasn0w. Ultrasn0w 1.2.8 is updated ios 6.it definitely works with iOS 6.1.2

I tested ultrasn0w 1.2.8 on iphone 4 iOS 6.1 and 6.1.2 with old BB 1.59.00. Not working.

i don't know about iphone 3GS.

It can't you would need to upgrade while preserving the baseband to be able to do this unlock

No, don't do this now! I've tried to unlock my iOS 6.1.2 iPhone 4 with ultrasn0w 2 days ago and my sim card has not been unlocked.
Fortunately I had my saved iOS 5.0.1's SHSH and now I'm running again on 5.0.1.
There's no ultrasn0w update for iOS 6.1.2 or 6.1.1 for the moment. Just wait a while like me.

Yes you are able to do it. Here is the way:
Step 1: Restore latest version iPhone2, 1_6.1.2_10B146_Restore ( after restore phone will in activation mode)
Step 2: Open redsn0w_win_0.9.15b3
Step 3: Extras > Select IPSW > iPhone2, 1_6.0_10A403_Restore > Open

Step 4: Back > Jailbreak
Step 5: Select install ipad baseband & unselect install cydia > next > put dfu mode (redsnow instruction) after reboot phone will activated
Step 6: Download evasiOn latest version and press jailbreak (for untethered your jailbreak )
Step 7: Go in Cydia and install ultrasnow while your simcard is inside (mine was inside from the first step)
Step 8: And reboot phone normaly
Step 9: After reboot your phone is UNLOCKED

It's best to google, but i have found for you suitable link you can try it! It will work.
http://www.unlockboot.com/2013/02/unlock-ios-6-1-2-iphone-5-4s-4.html

Yes ultrasn0w is capable if you upgrade to 6.1.2

Just you have to follow some procedure

1) create a custom firmware (6.2.1) using snowbreeze
2) now update your iphone 3gs using custom firmware
3) Once jailbroken head over to Cydia > Sources > and tap on the Edit button and enter the following repo "repo.iparelhos.com
4) now go to search install ultrasn0w fixer 6.1
5)Then install ultrasn0w
THE MOST IMPORTANT STEPS
6) uninstall ultrasn0w fixer 6.1
7)and reinstall ultrasn0w
8) reboot your iphone 3gs and wait for some min.
THATS All YOUR IPONE IS UNLOCK

Julien - you said you use iOS 5.0.1 and is working? I have the same iOS but my card don't work, can you help me about this? How can i unlock my phone?