The state of Vermont took my son from his father they have now given my sons grandparents temporary custody in the state of Vermont if I take my child and bring him to the state of New Hampshire what could happen to me??

Since they have temp custody, you will most likely have to go through the courts to try to get custody. If you take him now without their permission, it will not look good when you go to try to get custody. By law the grandparents are in charge of your son. You will have to fight in order to regain your rights. (And I'm sorry if any of the info I gave you was incorrect, this is what I believe the right answer is.)

So why don't you have custody? Why would it be given to the grandparents instead of the mother? This also has a big impact. Technically you could be charged with either kidnapping or interference with custody.

if i take my child and bring him to the state of new hampshire what could happen to me?????

You very well could be charged with kidnapping. All circumstances differ though, There is really not enough info in your question to give you very accurate advice.