Hello Vaishnavi,

To be eligible to secure a seat in NEET, candidate must secure marks equivalent to the Cut Off Percentile.

Keeping in mind last years number of candidates, the cutoff percentile was 50th percentile. 

For Unreserved category students, 119 marks were needed to be in top 50 percentile.

The cutoff percentile depends on the number of candidates appearing.

But For getting a very good rank one must secure atleast 510-520 marks.

Hope this helps

Thank You.