I went to what is now Darmstadt U.(Technische Hochshule then) in the 70’s under a foreign student quota. My husband at that time was a DOD employee working for Stars & Stripes. It was a terrific experience.
At that time foreign students had to pass a German language proficiency test and to have finished the equivalent of junior college or two years at a four year institution to begin the German Master’s degree program. At that time Germany had nothing similar to a Bachelor’s degree.
When my daughter started, she had to have a B1 level certificate...but they have hence eliminated the requirement at her school (classes are all in English).