With the acquisition of a French company, many licenses for Autodesk single products (such as AutoCad 2016) have been acquired. Can those licenses be used by French colleagues at the headquarters of the parent company in Germany?

Yes, you may also use these licenses in Germany if the corresponding maintenance or subscription contract has also been concluded in your Home Country. As a Home Country, Autodesk considers all member states of the EU. Autodesk describes these rights as Global Travel Rights.

Sources:

Official Autodesk Website, as of 12.07.2016 (https://knowledge.autodesk.com/customer-service/account-management/software-downloads/global-travel-rights)

Global Travel Rights_Autodesk, as of Juli 2016