Class 11

At first you should go through your NCERT books because for NEET maximum course is on the basis of NCERT. Then you may prefer some reference books like Universal for physics, CBH for chemistry and for biology NCERT is sufficient. You may also join crash courses or coaching for better preparation.

Analyze the various career opportunities in both the fields and decide based on your interest.

Kendriya Vidyalaya, DAV, etc.
These schools are reputed and provide good education also.
Delhi public school is also good in terms of education and discipline.

You have many options.
It depends upon your intelligence.
If you are smart, then go for B.Tech.
If you are ordinary, then go for B.Sc.
If you are not interested in study, then you can join animation design school.

If you wants to score good marks in less efforts then physical education is quite good one. Otherwise, in terms of opportunities computer is the best one.

Sure, you will be able to do so if you are able to clear the cut-off.
If you will not be able to get good marks in maths and have an elective subject as a sixth one then you can apply.
And the sixth one should be selected in class 11th only according to me. Also, it is only available in some schools.

Solve the previous year's question papers of KVPY rigorously. Find your loopholes, and work on them. First and foremost, you will have to completely study NCERT of 11th standard. Work on subjects like physics, chemistry, biology and maths.

Go thoroughly with the NCERTs of Standard XI and XII. Along with that, start solving as many as MCQs that you can. This will surely boost your confidence up.

You need to appear National Entrance cum Eligibility Test after completion of your 12th examination to get admission into medical colleges.
All the best.