For the Entrance examination conducted by All India Institute of Medical Science, there is no limit to the number of attempts. You may apply for the entrance exam as many times you want provided you fulfill the eligibility criteria mentioned below:
You must have passed higher secondary examination with a minimum of 60% with the subject combination of Physics, Chemistry, Maths and English.
The minimum eligible age is 17 years.
There is no maximum age limit to apply for the exam.