The standard thesis period at TUB is six months. Students can actually start more or less any moment they like as long as the supervisor agrees.
If you write your thesis in Berlin, you also need to register at NTNU otherwise we cannot give the 30 ECTS credit needed. See under NTNU "Master thesis agreement".
We will adjust the thesis submission deadline in the NTNU system in line with the TUB submission date. This will typically be a date in October, exactly six months after the start date (and not adjusted for any summer vacation).
Contact Ruud, Pedro, and Anne about who can be your formal supervisor at NTNU.