Hi Akhilesh,

As per the notification posted on AIIMS official website, the minimum marks eligibility says that all the general and OBC candidates need to score an aggregate of total 60% in English, Physics, chemistry and biology. 

If you are a CBSE student, then I would recommend you to sit for improvement exam to increase your marks. 

But if your best of four of these four subjects is greater than or equal to 60% then you are good to go.

I hope this information helps.

All the best.