Yes, if you apply for admission, you have to a approve that your level of German is at least B1. Which documents are valid, can be found under “Spezielle Kenntnisse 3” in the programme specific admission rules (German: Fachspezifische Zugangs- und Zulassungsregeln des Master Statistik, non-official translation into English: Subject specific access and admission rules for the ZSP-HU).

The mandatory course Stochastik I is in German but almost all others courses are held in English.