Hello aspirant,

At the time of result declaration of NEET UG exam you are provided All India Rank and All India category rank. After results, states announce their schedules for State counselling for medical courses in which they issue their own State merit list and new State ranks are being provided to students. This merit list changes every year due to various factors such as number of students attempted exam, and number of students participated in counselling, reservations and more. Instead in All India counselling only AIR is being considered.

Yeah there are benefits of reservation both in All India counselling and state counselling. For example the state cutoff for Calcutta National Medical College, Kolkata for unreserved category in NEET 2020 was 609 whereas the cutoff of SC category for the same college was just 508 marks and different according to their caste reservations.

Hope you get some clarification.