Hello, im going for vacation in Cologne ( Germany) and im thinking to take my mini 2 with me. It is allowed to fly or need registration or permits ( in my country doesn't need those )

Take a look at this website as it is very informative on UAV flying in Germany.

Hi there. Thank you for reaching out. We strongly suggest coordinating this with the local authorities in the region where you want to fly the unit. In addition, you may access the link below to check if there is a NO-FLY Zone in the area. Thank you for your valued support.

https://www.dji.com/flysafe/geo-map