Can i update my iphone to ios6?

I have an i phone4 and until now i'm on ios4. I have a jailbreak too… And i'm wondering if i can update to ios6 instead of 7 as in seven i may lose some of my main apps that are not yet updated.
so my first question is can i update to 6?
second. How about the jailbreak?
and if i can. How it's done?

No you will only the apps you have by jailbreak not that apps by apple store