For CBSE admission in Class 9 for the 2025-26 session, the student should generally be 14 years old by March 31, 2025 . Your son's DOB is 06 September 2013 , so by March 31, 2025, he will be 11 years and 6 months old , which is quite younger than the usual age requirement. Most schools follow the 14-year age rule , but some may allow exceptions. Hope it helps !