Final solution for 3gs 6.1 jailbrack and unlock@tested

Follow the step

1) dfu mode, downgrade to 4.1, ( you will get 1015 error,stuck in recovery mode)

2) open redsn0w, install cydia...( not ipad baseband (6.15) yet.phone should be turn on normally.

3) than open redsn0w install ipad baseband (6.15)

4) downgrade from 6.15 to 5.13

5) open sn0wbreeze 2.9.9, browse ios 6.1, choose simple mode ,chose activation. than do pwned dfu mode.

6) restore with created custom firmware.

7) install ultrasn0w 1.2.8