Clarification on getting admission of child against CBSE guidelines

sir, my son has passed out from class 1st. now i want to make his admission in class 3rd.because in future i want to make him apear in sainik school entrance for class 6 and also for navodaya school entrance class 6th. i have checked the eligibility conditions for both school. so to match his age in eligibility conditions, i need to make him appear in class 3rd. but school is refusing to accept him class 3rd despite the fact as he is topper and gain more than 90%.they are saying it as it is an illegal thing.but if i have given them examples of many students who have clreared their graduation at the age of 14. but still school is not accepting can you tell me how i can made it possible. and second thing the school falls under CBSE board and have a website that is mentioned compulsory according to cbse guidelines. but there are no details of school managing comittes and its memebers, no details about school staff members, even the contact number is not valid. so what action can be taken