My son freaks at exam time!!

To be able to help your son you have to first try and understand why it is happening. Without knowing exactly what the problem is then there is no way you can create a solution. I don't think mock exams at home with friends there as 'extras' will help as it won't however hard he tries be taken seriously and the same effects will not present. You need to sit down with him and try and get him to be totally honest with why the situation keeps occurring and then you can both work together to move forward

I think you should teach him to relax, with that he can think better. Why not try some mock tests at home, add some friends to make it like the environment in school, it's a fun activity too.