i am filing for termination of my child support obligation in NJ am i plaintiff or defendant

You're going to file for emancipation.  You will be either the plaintiff of defendant, it depends what you were on the original order for child support.  It is not automatic that your request will be granted, just because the child turned 18 and graduated.  If the child is going to college, you may not be able to emancipate the child. 

Were you the Plaintiff or the Defendant in the case where the child support order was entered?  You are the same thing in this application.  (The Caption of the case will be exactly the same).   Termination of child support can be tricky.  Was there a Court Order or written Agreement that said when child support terminated?  Are there any other children?  What is the child going to do after graduation?  Work and not go to college n September?  Work over the summer and go to college in September? Something different?  All of these things will be relevant to whether your application is likely to be successful or not.   I have more than 35 years of legal experience and head SALVAGGIO LAW GROUP LLC, a law firm which devotes its entire practice to New Jersey Family Law matters, including child support termination.  I would be happy to have a brief telephone call with you.  Of course, there is no charge for that phone call.  My firm’s toll-free telephone number is listed below.  Please also feel free to take a look at our Firm Website (www.salvaggiolaw.net).  I wish you the best. David F. Salvaggio, Esq. (877-355-5281)