If you wish to get seat in AIIMS Delhi then better to get more than 160 as this would be the safest score to reserve seat there. Apart from this, for reference you can go through below provided previous years cut off -

AIIMS Cut off

Hope this helps!!!

In order to get AIIMS Delhi you should try to score more then 150-160 marks in your exam under general category and more then 130 marks to get other AIIMS.

To check the cut off rank of all the campuses you can refer below link

AIIMS MBBS Cut Off

Good Luck!!