if you have passed your class 12 board examination with the minimum aggregate of 50% in each of physics, chemistry and biology and you are above 17 years and within 25 years of age for unreserved category candidates and below 30 years for reserved category candidate then you are eligible to set for the Neet examination and on clearing the cutoff and getting marks and percentile which will give you a drank decent enough to be held eligible for admission into a collage of your choice, you will be able to get into the college you want to after participating in the counselling based on the Neet marks and percentile.