Hello Abi, To become a professor in medical college you should follow these steps.
After 12 you should give NEET entrance exam.
For teaching medical students the minimum qualification is a post graduate degree in one of the subjects. Otherwise you can join as tutors usually on a temporary basis, aftet MBBS.
In order to become a professor Must hold a post-graduate degree in clinical or non clinical branch along with MBBS.
Must have three years teaching experience  in a recognised medical college as  resident/ Registrar/Demonstrator or a Tutor.
So if you are very keen on taking up medical teaching, better get a PG degree and then join as senior resident/Assistant professor in one of the medical colleges.
Hope it helps
Regards
Dr Parmanand Agarwal
MBBS MD
Career counsellor

that depends, you have two options to do that

path 1) after class 12th give NEET-UG and get yourself admitted into MBBS or BDS course, then do your MD/MDS or equivalent postgraduation ( many colleges in India allow Postgrads to teach some topics to undergrads but that solely depends on colleges.) by the time you are done with your postgrad you can apply for faculty position in various colleges, if you have done Ph.D it will give you a better chance. 

path 2) suppose you cannot make up to for MBBS or BDS you can do BSc ( biology/ biomedical sciences/biotech/ PCB and other biology-related courses) then you can go for M.SC ( clinical anatomy/ clinical physiology/ clinical biochemistry/ forensic sciences etc) and then apply as a faculty, since you are now tagged as "non-medico" you should go for Ph.D. to have greater chances of jobs as a professor.

 

Note: you can always do Msc ( clinical anatomy etc) after mbbs, bds, bhms, bams and join as a professor.

 

good luck!