Hello,

As per your requirement, i would say that as you have interest to be a inspector, you can follow this way, After 12th you will have to do graduate with your favorite subject...
Only then you will be able to face the competitive exams related to your desired post I.e 3 star police officer..
3 Star police officer is at least inspector of police which is a promoted post after Sub.Inspector for which you have to face exam for recruitment of Sub. Inspector of police (s.l)..
In this physical test ,, written exam and interview are held .. For another 3 star police officer (Dy.S.P) ,, you have to face state P.S.C exam in 3 steps - Prelims, Main and Interview..

Good luck