TBC - Current content BIS prot gear?

Hi there is there a prot warrior bis list for current content on Outland? (Kara/Mag/Gruul content)

Bis varies from guild to guild depending on DPS and healers. Generally you want as much survival as you need and then max out TPS. You need as little defensive gear you can get away with, with your guild's healers. The amount of TPS gear you need is dependant on your guild's DPS.

That being said I'm unsure how much you can mix and match in t4 content, someone who plays prot needs to fill you in there.

As has been said, there is no BIS for Prot, because it depends on a lot of factors that boil down to choosing between survival and threat, avoidance, armor, stamina. You could have the best avoidance gear in the game and come up against a spell damage situation where pure stamina would be much better, when tanking multiple low/medium damage targets then avoidance/block becomes king, but the harder the target hits the more value you gain from armor.

Also your dps could be so high that you would struggle for threat if you didn't prioritise threat gear (hit/expertise, block value, strength, agility etc). So you just need to try to build the best gear for your current situation, for dungeons you probably want lots of block value, hit rating.