How to unlock iphone 3gs ios 6.1.2?

So I've jailbroke my iphone 3gs ios 6.1.2 with a program calles evasion 1.5.3. After that I opened cydia and downloaded ultrasn0w. But my iphone still says it has no service. I'm using a sim card from the country I'm living in (brazil) but i don't think that should be the problem.someone please help me!

Stop messing with jailbreaks to unlock your phone. You'll just have to do it again later.

go here: http://gsmunlocklabs.com/unlock-iphone/

If you have problem in unlocking your iPhone 3GS with the current unlocking method, You can try any other safe unlocking method. For example, You can unlock your iPhone 3GS using remote unlocking service. This method of unlocking is safe, simple, affordable and quick. You can get the remote unlocking service for an iPhone 3GS from http://www.wickedunlock.com/apple-iphone-3gs/rs16wp9/ This method of unlocking doesn't require a jailbreak too.