No such things like interview are taken for AIIMS admission.
You will get seat solely on the basis of your rank. On the day of counselling all the candidates are asked to assemble in auditorium with their call letter, rank card, and required documents mentioned in call letter.
Documents are then verified and finally in the auditorium candidates are called rankwise and they are asked to select college based on the seats available and seat matrix.
After admission medical examination is taken to test for any disability and finally admission is confirmed .
For any queries feel free to ask …