Nedaří se mi instalace Adobe Photoshop 6 (zakoupený) na Windows 11

Please be more specific and describe you issue more detailed.

Which program are you talking about?

Do you get an error message? If yes, please post the exact mesage word-by-word.

This question has been asked and answered many times. You cannot install Lightroom 6 on a new computer, because that new installation requires activation and the activation server was taken offline. See this thread for a possible workaround: https://community.adobe.com/t5/download-install-discussions/lightroom-6-on-a-new-pc/m-p/14639307

To be clear. Are you talking about Photoshop, or Lightroom (a.k.a Photoshop Lightroom, at one time)?

Actually, that may not matter. Actual PS 6 and PS CS, are ancient and no longer supported by Adobe. The same for Lightroom v6. These predate the Adobe Plans, the subscription model. If you have the original CD/DVD or a copy of the install, you can attempt to install, But both may require a activation via a server that is no longer up and running.