what will happen if we do not attend ap diploma 3rd sem regular examination
If you are not going to attend ap diploma 3rd semester regular examination the only consequence is that you will not potentially be able to receive college credit for all the hard work that you did.if you are okay with it then its ok dont give it.
Also,you should contact your institute whether there is any other issues arises in future if you don't give this exam.the policy of your institute will decide the implications of not giving exam.
BEST OF LUCK