CBSE 10th

You have negligible chances for any good college.

Hi,
CS is a short study related to computer science. You can choose IT (Information technology) as a subject in your class 12th, which is a primary stage of CS.
Best of luck.

No, it is not possible. You have to complete your class 12th to join hotel management course.

Admission in IIMs is based on the entrance exam. The minimum percentage required is 60%.

Dear Writick,
Unfortunately with a diploma, you cannot apply to any German university. Students from India must complete 13 years of education and even if you have a diploma, it won't be accepted. That's how they work. What you can do is enrol into a Bachelor's degree in India, complete the first year. Another option would be to take the IIT JEE. The third alternative is to opt for Studienkolleg in a German university. I will advice you to refer to the websites of DAAD and UNI ASSIST.

Generally, most of the companies coming to any college for recruitment will specifically mention 60% in academics till date. Very selected number of companies would call for selections with 50% score or so. You need to wait patiently for your turn.

You can still score more marks in CMAT, if you start preparing from now. With your profile, I would suggest you to try getting more marks in CMAT. I also suggest you to apply for MAT exam. With 120 in CMAT and your profile, you may find it very difficult to enter decent institutions.