I'm talking about a document library on a SharePoint 2010 Server. In this library I want to add document sets and within some more documents. Is it possible to make sure that documents can only be added into document sets? So I want do avoid documents are uploaded on root level outside the document set.

Thanks for help

First you are asking SP 2010 question in Legacy SP version forum. :) Just an FYI for future questions.

Can you remove users permission at the root library level and give them permission at the Document Set level only? This way they can only read at the root level of the library.

Thanks for clarification.

No, different permissions are not an option for my case. The same person who uploads the documents is responsible for creating the document set.

Then it might be bit challenging. Do you have customization as an option?