Moved out of state

My divorce and custody agreement were granted in Gaston County in 2010 and I was granted permission to move to Indiana with my children (I have sole legal custody). She has moved all over the place and now evidently resides in Tennessee. She has had little or no contact other than an occasional birthday card. Now she has contacted me regarding visitiation with her expectation that I will bring them to TN for them to stay with her for a period of time. She is threatening me with court again. My question is with us having lived in Indiana for the past three years do I need to have the case moved here? If so, how do I go about that?

You would need to speak with a lawyer in Indiana about registering the custody order from NC in your current jurisdiction based on that now being the home state of the minor children. If your situation was reversed, there are means for you to do that in NC, but I cannot advise you on Indiana law.