Batter hits a fair fly ball that is catchable by the catcher. While attempting to field the ball catcher runs into the batter who hasn't left the batters box because he was hoping it would bounce foul. I have Batter interference/Out, no runners advance. What's your call?

if in my judgment the batter interferred with the catcher making the catch yes I would have INT. batter is out and no runners advance

I would say no interference for now, let me explain.
There was no intent on the batter to interfere based on his judgement/hope the ball would go foul.
Since the catcher is behind the batter it is up to the catcher to take a route needed that did not have to include the batter, unless he was also hoping for an interference call all along.
The batter is allowed to occupy his space even in the batters box, if there was intent to block the catcher then yes batter out. If there's no intent (based upon the umpires decision) then play continues.

BT40 here's a scenario to your scenario.
Runner on first, batter hit a pop up that is basically going to land on top of the bag at first, the runner stays put on first.
First baseman calls for interference, what's the call?
The call is let the play continue since the runner at first is allowed to occupy the bag and does not have to yield to the fielder.

Interference is a judgment call. When it occurs at home plate, the batter's box is NOT a sanctuary for the batter-runner. As B.J. said, if the umpire believes the batter-runner interfered with the catcher's attempt to field the batted ball, the umpire schould call interference. The batter should be out. As for the second scenario put forth by Mikelmart, it depends on the runner's action while standing on the base. Here is the wording from the USA Softball rule book: "A runner could be standing on a base and a defensive player bumps the runner while watching the flight of the ball. If the defensive player fails to make a catch on a ball that could have been caught, it is the umpire’s judgment whether or not interference should be called. The rule provides that a runner must vacate any space needed by a fielder to make a play on a batted ball, unless the runner has contact with a legally occupied base when the hindrance occurs. In this case, the runner should not be called out unless the hindrance is intentional."

The ball was in fair territory about 3ft in front of the strike mat the entire play. Once the ball was batted into fair territory he became a Batter-Runner, had he started towards first base the catcher would have had an easy play on the catch. I called interference as he made no adjustment on his position. His argument was that he was hoping it would bounce foul, which it never did. That right there confirmed my call as he should have been on his way to 1st.

@Mikelmart....In your scenario, I believe as a baserunner on a base that I could maintain my safe position on a base and allow for a fielder to have a fair chance at a ball. So what I'm looking for is if he is making an effort to allow for the fielder to make a fair play on a ball. In our league there is avoid contact at all costs rule implemented, so if a baserunner steps off a bag to allow for a fielder to make a fair catch, im not calling him for being tagged out if that happens. Unless he was actually trying to advance.

BT40 thanks for adding a little more detail to both scenarios.