Regarding age less than 14yrs for CBSE Xth std

Have a query regarding the age eligibility for CBSE board exam? Looking out for the cut off age? Find advice from experts on this page.

My son is 12 yrs now and studying 9th standard in CBSE. By next year 2018, he will complete 13 yrs and one month for Xth standard. Is he eligible for the exams?
I am worried. Can you provide guidance about what to do? His DOB is 06/02/2005. So what is the best option for me? He is capable of studying and good in sports and studies.. Also he has a huge built.