For most degree programmes, knowledge of German is a prerequisite for admission to German university. You can prove your German language proficiency by taking a language test, such as DSH, the TestDaF or the Goethe Certificate C2. The Goethe Institut Singapore offers the TestDaF and Goethe Certificate C2.

https://www.goethe.de/ins/sg/en/spr/prf.html

However, you don’t need to know German if you intend on enrolling in an international degree programme. For information about German language skills necessary for studying in Germany, please visit:
https://www.study-in.de/en/plan-your-studies/requirements/german-skills_26609.php