Hi there Fahii

Thank you for using our platform to clear your doubts. 

You must be aware of the fact that AIIMS is the topmost institution for the studies of medical sciences in India, whereas NEET is the examination that's conducted to enable admissions in all medical institutions. 

As AIIMS is the most reputable college, it attracts and provides admission to the highest strata of students who are meritorious. In order to lessen the number of applications and the competition the eligibility criteria is 60%. 

What I'm saying is through this 60% criteria AIIMS filters out students who aren't capable enough of getting into the highly esteemed institution. 

This might sound rude but yes if a student is unable to get 60% in boards then there are absolutely null chances of getting into AIIMS. 

Hope that clears your query. 

Wishing you luck!