I am looking for a list of all direct employment opportunities available immediately after 10+2 in India.

I think as long as long as the minimum age of 14 is met, the sky is the limit!
For example, most engineering schools require clearance of 10+2 with Physics, Maths. They additionally might require students to take common entrance exams to judge the intellectual capability of the student.
Same with Medical school except that it requires Biology to be studied as a subject in 10+1 and 10+2.

All these lines of work - Engineering, Medical, Defense require a lot of dedication and fcous from the student to continue the studies.