1. upgrade your baseband to 6.15 via red snow (redsn0w_win_0.9.13dev1)
to upgrade your baseband you have to do as you do jailbreak in options
select install ipad baseband.
2. after you install 6.15 again jailbreak with (redsn0w_win_0.9.14b1)and
select ( downgrade from ipad baseband )
then your phone will have 5.13 baseband
which can be unlocked with ultrasnow if you dont have wifi then use itools which is inside the
unlocking tool folder redsnow ultrasnow evevry thing is there inside
connect your phone select file system at left and click cydia drag and drop ultrasnow both the files
disconnect switch off swith on and use it
enjoy
regards
nasir
download link:::
iphone unlocking tools and instructions.rar