Unlike other countries, German universities do not give grants. The most important grant donor for international students is the Deutsche Akademische Austauschdienst (DAAD) (German Academic Exchange Service). Especially advanced students or graduates can apply for a grant. Get all the necessary informations about the DAAD scholarship programmes as well as offers from other selected funding organisations here: https://www.daad.de/en/studying-in-germany/scholarships/.
Furthermore you can apply for the Deutschlandstipendium (www.hs-aalen.de/deutschlandstipendium).
Other important points of contact for student funding are the foundations and organisations sponsoring talented students: https://stipendiumplus.de/studierende/. They, too, offer grants for international students. However, the conditions differ from one institution to another - oftentimes a very good command of the german language is mandatory - and have to be asked for from them directly. It might be rather painstaking, but can be worth it!
