Dear Hashif

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/no chances 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