Exam

Hi dear,
For admission into MBBS or BDS anywhere in India, you have to appear for only one common entrance examination and i.e. NEET. There's no other gateway for admission.

Well, you need to score 98ile+ to be in the premier league(CAT, XAT, NMAT, SNAP, etc), and 99.9+ile (CET, CMAT, ATMA, MAT) etc. Start your preparation now onwards. All the best

If you appear for civil services examinations after 10+2+3 with normal graduation degree, you will be able to earn faster. In medical you will take 10+2+5.5 years before you earn. Therefore, your argument has flaws.
Civil services examinations is very competitive. Therefore, it is good idea to appear

There is difference in general rank and category rank if you want to take admission with your category rank you have to seek the number of seats available in the college under your category.

It is an absolutely right decision to appear for CAT to seek admission in PGDM or MBA in India's top B-Schools. It will open door of opportunities for you.

You can sit for JEE exam but you cannot apply for counselling of NITs. As per the JOSAA scheme, you need atleast 75% in your 12th to be eligible for the counselling of NIT's.
Hope this was helpful.