In a large bowl, stir together the orange gelatin and boiling water until the gelatin is dissolved. Whisk in the Neufchatel cheese and mayonnaise until well blended. The gelatin should be slightly thickened and cooled.
Stir in the vinegar, carrot, pineapple, and fruit cocktail. Pour into a greased gelatin mold or serving bowl. Cover, and refrigerate until solid, about 4 hours.
To unmold, dip the mold into a large bowl of warm water for a couple of minutes to loosen. Then invert onto a plate to serve.
