The evaluation of application documents of international students and refugees for admission to university is handled by the Arbeits- und Servicestelle für Internationale Studienbewerbungen uni-assist e. V. in Berlin on behalf of many universities. These applications are free of charge for refugees.
To apply for admission to a university, you need to do the following:

1. Sit the TestAS first
Look for a suitable test date [link at the bottom].
Please consider the registration deadlines for TestAS
Find a test centre nearby
Use the information available on this website
Have a document ready for upload confirming your status as a registered refugee.

2. You may then apply to uni-assist
Send your application [application form] for the free evaluation of your university admission credentials to uni-assist
attach a copy of the document ready for upload confirming your status as a registered refugee
attach a print-out of your TestAS certificate
All prerequisites for an application to uni-assist are available here or at the university of your choice.