AIIMS has approximately 14 branches and these branches add upto 1400 MBBS seats across India. . Under All India Quota, All the 15% of All India Quota Seats except for Jammu and Kashmir, 100% Seats at Deemed and Central Universities, IP Quota seats in ESIC Colleges, Seats at AFMC, AIIMS and JIPMER are filled by DGHS. This is the first time that NEET is conducting its admissions through NEET score through All India Counselling and not State Counselling. We do have AIIMS Delhi's previous years cut offs. In 2018, 99.98 was AIIMS Delhi cut off for General Category. And in 2019, the highest NEET score was 701. Now AIIMS exam pattern and marking scheme are different from than that of NEET. While AIIMS MBBS was conducted for 200 marks and also included English and GK sections while NEET is conducted for 720 marks and only in Physics, Chemistry and Biology. Now AIIMS releases its results in the form of percentiles while NEET releases its score in the form of marks.  So going by this, you will need more than 650. Might be 675 will be a safe score given the fact that 99 .98 percentile is a higher cut off if you belong to General Category and 625 and more if you belong to Reserved Categories. This is an estimated cut off, And cut offs might change depending on various factors. Cut offs change every year depending on various factors such as no.of Candidates appearing for the exam, no.of Candidates qualified, top NEET score and difficulty of the exam. Each branch might have different cut offs. AIIMS Rishikesh might not need the score that AIIMS Delhi might need. So in general if you belong to General Category you will need more than 600 and for Reserved Categories, you will need more than 575. This again depends on the AIIMS branch.