Hello, i have a problem with the location, gametacker tells me, that the server is in russia, but ins in Frankurt, Germany. How to change that?

On the server page, you'll see a link for None - Claim Now! or (claim server). Upon clicking that, you'll be taken to a page with a Claim Ownership button along with instructions that can be found by clicking the (?) near it. Once you claim it, you'll be able to change the flag on that page.