Hey as per my idea last date for applying is over as it is too late now but you can try for next time and here I am giving you its details

Qualification
Candidate should have done masters from recognised university

Selection criteria
On the basis of Written Test
On the basis of Interview

Important Dates
Date of Uploading Prospectus & Registration of Online Application through Web: 02nd May 2016
Last Date for Online Registration of Application on AIIMS Website: 25th May 2016 (up to 05.00 pm)
Applicants are required to check on 21st June 2016 through the Registration Status Tab of their My Page after Login: 20th June 2016
Last, Date for Submission of Required Documents for Regularization of Rejected: 29th June 2016
Last Date for MHFW, Govt. of India to forward an approval regarding ‘No Objection’ to the Foreign National for appearing in the PhD Exam for July 2016 Session: 29th June 2016
Finalization of Centres & Allotment of Roll No. /Admit Card on Website: 05th July 2016
Date of Exam Doctor of Philosophy (PhD): 16th July 2016 (Saturday, 10.00 am to 11.30 pm, Centre: Delhi/NCR)
Expected Date of Declaration of Result: 20th July 2016 (Wednesday)
Departmental Assessment: 26th July 2016 (Wednesday)
Date of Final Result: 29th July 2016 (Friday)
Last Date for joining the PhD Program: 31st August 2016 (Wednesday)

Address
AIIMS
Ansari Nagar East,
New Delhi,
Delhi 110029