B.Sc Nursing is a 4 year full time course after your 12th. For admission to B.Sc Nursing, you should have completed your 12th with Physics, Chemistry and Biology as core subjects. Admissions depend on the Institution you want to study in. For example, AIIMS has an entrance examination and you need a minimum aggregate of 55% in your 12th. It is 50% for Reserved Categories and 55% for General Category. And Indian Army B.Sc Nursing also has an entrance examination. But few colleges conduct admissions based on the merit scored on your 12th. And Colleges in Maharashtra conduct their admission to B.Sc Nursing based on your NEET score. Once you complete the course, you join as a Staff nurse and slowly grow up the ladder to become a Head Nurse. You can also study MBA or M.Sc Nursing or any other Health care related courses.