Dear Aspirant

According to 2018, the last rank at which the seat has been allocated was AIR 2212 and OBC Category rank 540 at AIIMS Mangalagiri. There might be low chance as new 6 AIIMS have been introduced and OBC seats are increased to 324 (including 81 seats in new AIIMS).
For more information, you may visit https://medicine.careers360.com/articles/aiims-mbbs-cut-off or can comment for more queries.
Note: Merit list changes every year and only on that basis the admission is done.
Hope this helps you