I updated my iphone 4 version to 5.1.1.. can i do a full unlock online or how can i unlock it?

iPhone: About unlocking

To unlock your iPhone, check with your carrier to ensure that they offer unlocking and that you meet the requirements to obtain an unlock. If both those requirements are met, ask your carrier to unlock your iPhone, then follow these instructions:

1. Ensure that you've waited the recommended wait period provided by your carrier.
2. Back up your iPhone.
3. Erase the contents of your iPhone.
4. Swap the old SIM card with the one for the new carrier.
5. Complete the setup assistant and restore your backup.