Can I unlock iPhone 4S iOS 6.1.3?

I have an iPhone 4s with iOS 6.1.3 that is locked. The baseband is not the latest one.
is there any way to unlock it by myself?

You can get your Iphone 4s unlocked using remote unlocking method. You can get this service from any vendors online like Mobileunlocksolutions.com

You can have your phone iPhone Factory Unlock remotely. I suggest that you get an iPhone Unlock service because they use a tool to access the carriers IMEI to unlock it.

Yes, as far as I know. Try using a professional unlocking service and they will determine if your baseband is available for unlock. I used the following service with good luck: http://www.unlockroom.org.

Jailbreak?