how to factory unlock my i-phone 4s

[shehzad678]

Hello friends,
my brother brought a i-phone 4s from UK since then m using it on temporary unlocking system here in india. But, whenever i travel to some distance network getting disappeared. I can't even upgrade any advanced iOS in it plz guide me to overcome with this issue.

thanks & regards,
Shehzad

 

[J. A.]

The original carrier needs to unlock the iPhone, otherwise you'll not be able to use it properly.