I got low percentage in 12th board and i am perparing for aiims . I need to get improvement exam in all five subject or in any one subject

If you do not have the minimum marks that is required for cracking AIIMS in 12th,then in order for being eligible for admission through AIIMS, you have to take the improvement exam. So, if you have score more than the min. Eligibility criteria , then there is no need for giving improvement in all the 5 subjects.

But if you don't have the required percentage, then you have to give improvement exam in all 5 subjects, as the AIIMS authority doesn't want to look to your two different report cards.

Dear Aditya, the minimum aggregate that you need to score in Physics, Chemistry, Biology and English alone is 60%. It is 60% if you belong to General/OBC Categories and its 50% for SC/ST. You need to pass each subject individually and scire this aggregate against your Category. Now you havent mentioned your Category. Now if you have scored 59% aggregate, in these 4 subjects, it makes it easier for you if you appear in just one subject or 2 max for improvement than sitting for all the subjects. At the end of the day, it is the aggregate that matters. Instead of apearing for all subjects again, pick 2 subjects of your choice and appear for them.