Hey Vaishali! Definitely a state board student can crack the AIIMS exam the thing is just you have to channelize your efforts in the right direction and work hard. exam contains 200 objective type questions including MCQs and reason-assertion questions from Physics, Chemistry, Biology, General Knowledge and Aptitude & Logical Thinking. The marking scheme is

• +1 marks for each correct answer
• -1/3 mark for every wrong attempt
• 0 mark for unanswered questions

Hii aspirant..

Yeh of course State board students can qualify for AIIMS. I don't think that you should feel or see yourself down of being a state board student. The Candidates must have passed class 12th examination or equivalent from any recognized board. Physics, Chemistry, Biology and English must be main subjects in class 12th examination. A minimum score of 60% for General Category and Other Backwards Castes and 50% for SC/ST is required . And if you fulfill the above eligibility criteria then just start working hard and I sure you that if you are really dedicated and hardworking and you will surely qualify for AIIMS.

Hope it helps. 

Best of luck