You haven't mentioned your Category. Neverthless, AIIMS will condcut admission to its 1500 seats through All India Counselling there by leaving no State Quota chances. All this while, AIIMS had its own entrance and admission process. It released its results in the form of percentages. The exam was for 200 marks including English along with conventional Physics, Chemistry and Biology. Now NEET has only Physics, Chemistry and Biology and the exam is for 720 marks. And NTA releases NEET scores in the form of marks. These are the basic differences between AIIMS and NEET. Now putting aside all these differences we shall try to convert the percentages to scores to help you with an ideal score to get into AIIMS. In 2019, the cut offs for various Categories for AIIMS has been as follows:

General Category: 98.833

OBC: 97.011

SC, ST: 93.65

When this is roughly converted for 720 marks, it might be more or less this way:

General Category: 705-710

OBC: 695-705

SC,ST: 650-680

Now this is 2019 data and 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. In 2019, 701 was the highest score and the ranker chose MAMC. Now with AIIMS and JIPMER also joining NEET counselling, the competition is only going to get tougher. You can benefit from our MBBS Companion which can help you predict Colleges for your score and clear your questions regarding counselling: https://www.careers360.com/mbbs-companion