Hiiii Shivangi!!!! The course of polytechnic is similar to the course of any corresponding bachelor's discipline. The basic difference is that the graduation course is a degree course while polytechnic is a Diploma course which you can do after 10 or 12 and it will simultaneously cover the 11th and 12th part.

Hi,
Its not essential to do the 11th and 12th after doing the 10th Class if you want to make career in through Polytechnic course
After doing 10th with good percentage you will get admission in the best govt. or private institute for Polytechnic
You can make good career in the Railways after completing the polytechnic from the recognized Institute
You can make career as a RRB LOCO PILOT.
The RRB ALP and RRB Group D Vacancies are out and govt. recruits for the various posts for Polytechnic Exams

More information through the links:
https://engineering.careers360.com/exams/ap-polycet
https://engineering.careers360.com/articles/ap-polycet
Hope it helps.