Career

There are many institutes across India to prepare for the JEE Mains, but there are some coaching institutes in India which have only name and fame.
Kindly specify your location.

It has a great scope if you are really interested in it. After doing so, you have options in research in various medical electronic machine areas. You can either go for a job. It's better to do Masters for the best jobs in this field.

Best career option for student with computer science is to B.Tech CSE or B.Tech IT because these degrees are the most accepted graduation degrees to become a software engineer. Students with Computer Science in 12th board has a relatively advantage over non CS students during initial 2 to 3 semesters of B.Tech CS and B.Tech IT.

You have to wait for next year because without NATA and JEE Mains you cannot take admission in any college.

MS Excel, which I believe you mean Microsoft Excel, is a tool friend. You need to be an expert in various other tools with a multidisciplinary & smart approach to challenges in the jobs of accounting & bookkeeping as a commerce graduate or you need a tech experience & expertise in the software programming if you dream of an accounting software development job.

You can go for B.Com+CA or you can also go for B.Com+MBA, BBA+MBA provided you do MBA from a good college so that it would be better for your future and career growth.