If the car is running and you put it in gear and hit the gas and it doesn't go anyplace and it doesn't stall, your torque converter or front pump is gone or your not really in gear.
If you do stall, then your torque convert is fine, your front pump is fine, something is broken down stream of that.
Does the parking lock engage so that you can't push the car (when it's in park) AND if you move it to neutral, will it then roll?
If you pass those two tests and have room to push it, put it in first and push it "fast" (as in 10mph) and see if the engine has turned. If it doesn't you have some form of hydraulic failure.
Those are the best tests I can think of to diagnose it w/o dropping the pan and removing the valve body to do a pressure test.