In 2018, the last rank to get selected for mock counseling was 1600 so you might not get a chance to get admitted to AIIMS. The cut off of AIIMS MBBS 2019 is the minimum required percentage which needs to be scored in order to qualify for the exam. 

Here's a link that will help you out with the cutoffs for all the centres of AIIMS:

Https://www.google.com/amp/s/medicine.careers360.com/articles/aiims-mbbs-cut-off/amp