Sorry to say there are no particular scholarship particularly for exam. However, based on your state government provisions, you might be entitled for sc and you need no exams to give for it. You just need to register in their respective website and submit necessary documents. Exam based scholarship is provided for NTSE(National Talent Search Examaniation) which provides you an annual scholarship during your graduation days not just AIIMS or Medicine. The exam is conducted for 8, 9 and 10 class standard students.

The other exam is All India Sclolarship Entrance Examination for medical and engineering students. You need to apply online for the examination and complete the application process just like any other competitive exams. Here is the link

https://www.aisee.co.in/