1996, stuck in park shifter moves fine, but car will not roll in neutral, but if i rock car back and forth it will pop out of park and then i can drive forward and backwards just fine. as soon as i put it back in park its stuck again. fluid level is fine.

Um, what kind of transmission? Standard or automatic? What gear?
Generally if it's an automatic and stuck in drive or reverse it's probably a linkage issue ...something's out of adjustment and you'll need to get under the truck to sort it out. If it is stuck in Park, then try rocking it backward or forward while some tries to move it out of park ...sometimes the parking awl gets hung up when the vehicle rolls a bit after you put it in park.
If you have a standard tranny then there is something amiss internally. Modern standard floor shift trannies do not have any external linkages to go out of adjustment. You might try rocking the vehicle back and forth while someone tries to move the shifter to neutral. But if it's jammed chances are it is something internal that's failed.

Sounds like your linkage adjustment slipped. Chock your tires...jack up if you can't fit underneath it...have a helper move shifter back and forth so you can locate where it attaches to transmission. When you find it, have your helper move it from low to park slowly. When you see what way the piece on trans is moving, loosen the adjustment screw, manually place trans in park, then tighten adjusting screw.

Have the car towed to a local transmission repair shop, they can give you a preliminary diagnosis in most case at no charge

Usually the problem of not getting out of park is caused by the brake switch or the solenoid that locks the shifter in park.
The brake switch cuts off or applies power to the solenoid.
But if you have to rock the truck to get it out the problem could be something inside the transmission.

Rock back and forth , take it out of AWD , Put parking brake on shift into Park .

rock steering wheel back and forth, while turning the key, rock vehicle back and forth to take pressure off transmission shifter. are you parked on any kind of up or down hill grade? if so, that's the problem. start using emergency brake before putting in park.

Tip on end of park rod has slipped and is staying in the park position. Put car in neutral and get out and rock car back and forth by hand. Tip will slip out and car should move. This will not fix the tip problem as they are crimped on and the crimp has slipped. I installed a master electrical switch and never put the trans in park. I start and stop car in neutral and use switch to shut of electrical. Costs $ 800 to fix trans as park rod is last item out of trans. Cheap solution for me as car is a beater and am driving until it quits. Best of luck.

Try rocking the truck back and forth.

You may have a bad neutral saftey switch. Or the Linkage in the column has become disconnected, or tangled. Note the ignition switch may also be bad ( locks the shifter inpark)

I, as well as a guy I work with both drive s-types. He had this problem with his.

The problem is with a cable that runs from the shifter to the transmission. There is a bracket which holds the cable in place. This bracket is prone to coming loose and when that happens, your s-type won't shift out of neutral. Simply resecure the bracket and cable. Be sure to use loctite on the bracket screws so it won't happen again.