I CAN'T FIND ANY CHEATS OR CODES FOR THE ORIGINAL XBOX,CAN ANYONE SUGGEST A SITE FOR THE OLD XBOX,NOT ALL OF US CAN AFFORD A XBOX 360?

Jaxson, there is no direct code to enter for the jet pack. However, I will give you a link to the available cheat codes for 360, and a video showing how to get the jet pack. ^^ (Warning) it's not fun to get it. It takes for ever. Furthermore, I thought you were originally wanting the codes for gta V. lol So for gta 4 there is no real code for the jet pack, just a helicopter emulator mod from photoshop.
GRAND THEFT AUTO IV Cheat Codes

GOD 1

indeed i do on this website Batman Arkham City Cheats Codes Unlockables Xbox 360 IGN

This completely differentiates upon the game. Every game with cheats will have a different way to access the cheat keyboard and I would suggest either specifying which game you're talking about on here or look up on forum or wiki sites for that game on how to open up the chest keyboard.

Due to this being asked for Xbox though, I should say, see if the game you are looking up cheats for actually has cheats available on the Xbox console, because not all games provide cheats for every console.

I don't use such codes myself, though know others who do.Unless I missed something, you don't mention the name of the game or the console. If it's an XBox original or an XBox 360 I can probably help you. Let me have the details. ;0

mortal kombat characters wont be unlocked with cheat codes you should have enough koins and go to krypt and search for them

you should be able to find cheats on cheat code sites like cheatcc.com or one of the other few cheat code sites they should help.

no code a figur on the portal of power sorry for my speaking!

There are hints, not cheats. Essentially they are tips to help unlock features, find hidden areas, etc. I will attach a link here that shows all the hints that I can find.

http://www.cheatcc.com/xbox360/beowulfcheatscodes.html

You can unlock characters or content with origins in other games but it is not possible to download full games with a cheat code