M.S in Germany

75 to 80% in Bachelor's with IELTS 6.5 or TOEFL 550 is accepted. Other than that, you need research, publications etc. and recommendations from your professors or employer with a CV to apply.

You are eligible for MS application in German university for summer admission (session starting in Aug-Sep 2017). Summer admission will start in majority of universities in Dec 2016-Jan 2017. Different universities have their own admission calendar. You are requested to look at website of targeted universities for exact details.

It depends if university doesn't have holistic approach for admission review. They may consider conditionally, however 315+ always recommended.

Hi,
For all countries abroad you require GRE and TOEFL score for MS degree.
There are a lot of courses in Germany which are in English language. Please check on masterportal.com

You need to get admission in a university, not college. Check out the link mentioned below:
https://www.daad.de/deutschland/studienangebote/international-programs/en/?p=l&q=mechanical°ree[]=2&fos=0&fee[]=0&sortBy=1&page=1&display=list

Getting a free seat is almost a 'no'. You must be extraordinarily bright to get into a national university with no tuition fee. Unfortunately a score of 6.4 is very low. If you can manage to get a CGPA of at least 8 out of 10, chances of admissions would still be there in a few universities. But, tuition fee is anyways minimal in Germany.

Your UG score should be 2.3 or lower out of 6, it means over 75% marks in Bachelor degree, with minimum 6 band in IELTS or 79 in TOEFL. If your UG score is lower than 75%, try for GRE for profile boost.

Germany is a country, where technological fields are booming and with quality because they always choose best for their need, so when they choose a foreigner, they first attract by him/her academic record. So, it is definitely tough to get a chance there, but never lose hope because you are an automobile engineer and automobile industries are expand in Germany every day.
You have a chance, so you can choose German taught courses instead of English taught courses, then you can get admission there and it will also help you to get a job there. Extra-curricular activities, projects will also help you.
All the best.

German universities do not follow any ranking, they are equally good and competitive. The most popular ones in terms of research activities, employability rating, international orientation, etc. are:
1. Tu Darmstadt
2. Tu Kaisserslautern
3. Tu Munich
4. RWTH Aachen
5. ULM University
6. Illmenau institute of Technology
7. University of Stuttgart

I think you should apply for MS in USA because it is better than Germany for all the fields.