Can I give people a option to download barotrauma in my own polish language version from jumpbox? Do I have permission? I am editing english words using xml files.

Yes, feel free to publish it. :) There's one thing to note though, the EULA prohibits releasing standalone versions of the game, meaning that you should only release the files needed to translate the game, not a full game that works out of the box. At this point it doesn't make much difference because the game is available for free anyway, but something to keep in mind.

Thank you sir, but every time I use polish signs like ł or ź the game don't recognize them and goes crazy with everything.