Is it possible to jailbreak iOS 6.1.3 on iPhone 4S?

Is it possible to do so?
I have googled it and i don't know who to trust, some sites say it can't be done, some say it can be semi tethered where when the phone is rebooted only official iphone apps will work until you connect to pc.

I have jailbroken before, id prefer if it was an untethered jailbreak!

Just like a definite answer and a website if possible, Cheers!

There's none.