Choose your city to see tutors. AIIMS experience is ranked first — results are not restricted to it.
There is no separate AIIMS entrance for MBBS any more. The AIIMS institutes admit undergraduate medical students through NEET-UG, along with every other medical college in the country, so a student searching for AIIMS preparation is looking, in practice, for NEET preparation.
The merger removed a real difference between the papers. The old AIIMS exam carried general knowledge and an aptitude and logical-reasoning section alongside Physics, Chemistry and Biology, and students prepared for it as a second exam with its own habits. NEET is the three science subjects alone, with Biology carrying the largest share of the questions, and an AIIMS seat is now a matter of rank and counselling rather than a separate test.
The name still has an exam of its own further up. AIIMS and the other institutes of national importance admit postgraduate candidates through INI-CET, which is separate from NEET-PG. For a school student or a repeater, though, the useful brief for a tutor is a NEET brief — which of the three subjects is holding the score down, how much of the Class 11 syllabus is still shaky, and how much time is left before the next attempt.