2000 Cadillac deville starts but when I to shift into drive the shifter moves but indicator stays in park I moved the shifter to neutral and was able to push the car so I assume the linkage is fine but when I move the shifter to the drive position it won't move

Sounds like your linkage has separated.... but, first check the transition fluid make sure it is full and use the correct type for your brand of car.... the linkage goes from the bottom of your shifter and hooks to the transmission...as you move the shifter in the car it selects a gear on the tyranny by physically moving a leaver... a lot of times they are cable or leavers but some are electric..

Neutral safety switch get one from napa auto

It may be detached from the opposite end, Anthony. That transmission may also have (probably DOES have) a "PRNDL" switch on one side of the transmission. That switch may have failed.

If the fluid level is ok then you need the transmission repaired/rebuilt.

Either you have a broken shifter, cable or possibly the range sensor (also known as the neutral safety switch).

you can shift it at transmission by hand to neutral or park and have someone inside start the car and you manually put in gear under hood and drive it to shop or garage, wherever

A lot of vehicles used a wire to run indicator hooks from column to indicator may be able to see from underneath.

Still sounds like the linkage at the transmission. Take another close look while someone is working the gear shift lever.

Use like reference guide for GM Cadillac 1967-1989 Repair Guide Neutral Safety Switch - REMOVAL & INSTALLATION

All Except 1985-89 Eldorado and Seville
See Figure 1
The neutral safety switch prevents the engine from being started in any transmission position except Neutral or Park. The switch is located on the upper side of the steering column under the instrument panel on column shift cars, and inside the shift console on floor shift models.

1. Remove the console for access on floor shift models.
2. Disconnect the electrical connectors.
3. Remove the neutral switch.

To install:

1. Place 1967-70 column shift lever models in Drive, and 1971 and later models in neutral. Locate the lever tang against the transmission selector plate on column shift models.
2. Align the slot in the contact support with the hole in the switch. Insert a 3 / 32 in. (2.38mm) diameter pin in place. The switch is now aligned in Drive position.

1973 and later neutral safety switches have a shear-pin installed to aid in proper switch alignment so that insertion of a pin is unnecessary. Moving the shift lever from Neutral shears the pin.

1. Place the contact support drive slot over the drive tang. Install the switch mounting screws.
2. Remove the aligning pin. Connect the electrical wiring, and replace the console.
3. Set the parking brake and hold your foot on the service brake pedal. Check to see that the engine will start only in Park or Neutral.

Fig. 1: Installation of a common neutral safety switch



ADJUSTMENT
See Figure 2
1974 and later cars do not have a neutral safety switch. Instead, these cars have an interlock between the lock and the transmission selector, which is non-adjustable.

1. Place the shift lever in Neutral.
2. Move the switch until you can insert a gauge pin, 3 / 32 in. (2.38mm) diameter, into the hole in the switch and through to the alignment hole.
3. Loosen the switch securing screws. Remove the console first, if necessary.
4. Tighten the screws and remove the pin.
5. Step on the brake pedal and check to see that the engine will only start in Neutral or Park.
   

Fig. 2: Adjustment of a common neutral safety switch


1985-89 Eldorado and Seville
See Figure 3

All neutral safety/back-up light switches come with a small plastic alignment pin installed. Leave this pin in place.

1. Place the shifter assembly in the Neutral position.
2. Remove the shifter lever-to-switch nut and the lever.
3. Disconnect the electrical connector from the neutral safety/back-up light switch.
4. Remove the neutral safety/back-up light switch-to-transaxle bolts and the switch from the vehicle.

To install:

1. Position the shifter shaft in the Neutral position.

If using an old switch or the plastic pin (new switch) is broken, install a3/32in. (2.38mm) diameter pin gauge (drill bit) into the neutral safety/back-up light switch; the switch is then locked into its Neutral position.

1. Align the flats of the shifter shaft and the neutral safety/back-up light, then, align the switch-to-tang on the transaxle. Torque the switch-to-transaxle bolts to 22 ft. lbs. (30 Nm). Remove the pin gauge.
2. To complete installation, reverse the removal procedures. Make sure that the engine starts only in the Park and Neutral positions.
   

Fig. 3: Neutral start and back-up lamp switch - 1985-89 Eldorado and Seville

Hope help with this (remember rated and comment this). Good luck.

replace park neutral switch located beside the shift cable