Computer Science and Engineering

CSE is a better option.

Germany is the home for top automotive brands in the world i.e. BMW, Audi, Mercedes, etc. So, it's definitely a great choice.

Even though yours mathematics is not so good, CSE is best for you because it has good scope. Moreover, you need to study mathematics only for the first two years.

IIIT Hyderabad is the best for M.Tech CSE because of its world class faculty.

There are plenty of government/PSUs jobs waiting for you. You must prepare yourself for different competitive exams to get them.
You can check the below mentioned links:
Computer engineer career options:
https://www.shiksha.com/career-as-computer-engineer-cc-31
List of government job available for com

It is relatively easier to compete for CSE jobs, while studying ECE. CSE preference may be there for few high profile jobs like Cisco, Microsoft, Google and so on. At the same time, ECE students will have an edge for telecom jobs. So, go for the branch which really interests you.

Both the streams are good and in demand. You should look for the better colleges and choose accordingly.

There are so many branches in computer science engineering. You can also join mechanical because all the work is done with the help of software, but you need strong coding.

You can check the below mentioned link:
https://www.shiksha.com/b-tech/course/b-tech-in-computer-science-and-engineering-school-of-engineering-and-technology-ansal-university-gurgaon-751

You can check the below mentioned link:
https://www.shiksha.com/engineering/colleges/m-tech-colleges-hyderabad