Date of Birth
Only those candidates whose date of birth falls on or after October 01, 1988
are eligible. However, in the case of Scheduled Caste (SC), Scheduled Tribe
(ST) and Persons with Disabilities (PwD) candidates, upper age limit is relaxed
by 5 years, i.e. SC, ST and PwD candidates who were born on or after
October 01, 1983 are eligible. Date of birth as recorded in the Secondary
Education Board/University certificate will only be considered

JEE Year of Passing Qualifying Examination (QE) Main 2013
Only those candidates who have passed their Class 12th Exam or any other
qualifying examination in 2011 or 2012; or those who are appearing in their
Class 12th Exam or any other qualifying examination in 2013 are eligible to
appear in JEE (Main) – 2013. Candidates who passed Class 12th/Qualifying
examination in 2010 or before as well as those who will appear in such
examination in 2014 or later are not eligible to appear in JEE (Main)-2013.
Candidates who appeared in class 12th/other Qualifying Examinations in
2010, did not pass in 2010, but passed in 2011 are also not eligible to appear
in JEE (Main) 2013.
Candidates must have taken at least five subjects in class 12th/any other
Qualifying examination in order to be eligible for writing JEE (Main). In the
year 2013 however, the candidates who have taken four subjects are also
permitted to write JEE 2013 as an exception.

http://jeemain.nic.in/jeemain2013/pdf/JEE_Main_bulletin_07_11.pdf