Which is the best age to join a kid at school

As usual more people will put their children when he is 5 years old. In my view it is usually better to put children more than 5 years of age. Because the child can clearly understand a lot of things the more clearer he is. To Tune him in ways which he loves to do such as if a child likes to play music put him in some music institution to learn or if he is interested in games put in which game he likes.