Hello student if you're concerned about MBBS course. Admission in AIIMS MBBS is through Neet entrance examination.

ELIGIBILITY - Candidates must passed or appearing class 12 in physics chemistry and biology with minimum 50 percent marks from a recognized board.

As you've also tagged AIIMS nursing

Admission in AIIMS nursing is through entrance examination conducted by AIIMS Delhi - All India Institute of Medical Sciences Nursing

ELIGIBILITY - Candidates must passed or appearing class 12 in physics chemistry and biology with minimum 60 percent marks from a recognized board.

Cut off vary every year on various factors like level of questions in the examination total number applicants and seats offered.

For more details refer to the link mentioned below - https://www.google.com/amp/s/medicine.careers360.com/exams/aiims-nursing/amp

Feel free to comment if you've any doubt

Good luck