If you are planning to apply to under- or postgraduate program, etc. at the German higher education institutions in the German language, you must have a higher education entrance qualification (e.g. higher educational diploma “School Graduation Certificate” or under- postgraduate degree) from your home country and it must be recognized in Germany.
In most cases, applicants with higher education entrance qualification from their home countries, they can not directly jump into the German universities to study in the German language!
To check the Recognition and the Eligibility to study in Germany, we recommend you use these following database links for admission requirements (https://anabin.kmk.org/anabin.html or https://www.uni-assist.de). Or you can directly contact the desired university to know the essential two objects about your higher education entrance qualification:
In case your previous qualification is recognized in Germany, you will most likely (in most cases) go through either, A) Foundation Course/Foundation Year “Studienkolleg” or B) Preparatory Course e.g. DSH, TestDaF, etc. certificate to make your qualification eligible to study at the German university level.