Both.
You should check your brix/gravity once the honey is added, and then again after the fruit has been added. In many cases you'll find that your gravity has come down lower than you expected due to the juice being lower in brix/gravity than your honey must. It's also a good idea to take a fruit sampling at random (juice/crush up about 20 berries, some peach slices, or if you're using juice just measure it from the container, as long as you have a representative mixture of fruit/juice to get a good reading) before you add it in so you can calculate out how much the juice/fruit will dilute down your honey must gravity. There's a good tool in the Mead Calculator that will help with this.
Cheers,
Oskaar