It's not free. There is no tuition, but at least in TUM (Munich) there is a 'student union and basic ticket' free. It's €129.40 per semester [1]. There are financial aid options available. This applies to all students regardless of nationality.

TUM is a top technical university by German, European and World standards. [2]

[1] - https://www.tum.de/en/studies/fees-and-financial-aid/ [2] - https://en.wikipedia.org/wiki/Technical_University_of_Munich...