M.Sc Cut-off

For M.Sc in physics, you need to have minimum 50% marks in B.Sc in physics.

There is no cutoff for integrated courses. You will be given 50 questions out of which 40 questions are from major subject and other 10 questions from other science subjects like if you are a physics major student, the other 10 questions will be from (mathematics, chemistry, biology or computer and GK). So it basically depends on the student's score.

Dear Jaspal,
Yes, B.Tech percentage does matter in pursuing MS courses in Germany. However Universities do not mention and specific cut-off on their site because of 2 reasons:-
1. Universities abroad evaluate a person's overall profile than just specific scores. For ex: - 10th, 12th, Bachelors scores, work experience (if any), extra-curricular etc.
2. As Vikas rightly pointed out, cut-offs for admission keep changing from year to year depending upon the type of applications received. However they are generally very high for German Public Universities.