Compliance and Redirection Issues

Please remember that I have to maintain compliance with very strict EU privacy laws in Germany.

I have my Website structure from a user perspective based on where he accesses the website from

Language>City>

My main Homepage, however, Needs to Redirect to based on that

I was thinking to use a Popup with ... Chose your Region>City

Each City page has it s own listing System, and I Need that in order to be able to offer a better UX and sell better adverts.

There is also the IP Redirect Option, any idea how to do that, without using a plugin that does that by ...and there is the tricky part.... no IP data stored on the plugin Service Provider.