HI I have received a response from a potential buyer of my 2001 Nissan PathfinderHow do we complete the transaction if we are located in different cities and states?Can you provide guidance or support for the procedure for title transfer or transfer of the car to the buyer

The buyer should come to you, and you should complete the sale and title notarization & bill of sale the same whether the buyer is from in state or out of state. It's up to the buyer to then obtain temporary tags from your state's registrar (all they need is the title signed over to them) and once they have the vehicle back home, they can transfer the title and get their plates. Most states may require a VIN inspection when registering out of state titles, but again that is on the buyer.