The transmission selector says drive and reverse . Though the car will not move. Then it says transmission failure, drive to dealer slowly.could it possibly need filter change and new fluid?

auto transmission -check the reverse servo/ solenoid operation
manual transmission--check for loose selector fork for reverse , broken selector fork, stripped reverse gear, reverse gear key failure

Transmission may now be toast since you continued to drive it when maybe low on fluid or torque converter had failed. How long since last fluid and filter change? Ever?

Well, if you move the gear selector and the transmission goes from park to reverse, neutral, and drive then it is probably good. If you move the gear selector and the transmission does not change then there might be a problem.

check the selector is adjusted and tight as you may be selecting the last of the gears as it moves . When stopped -place it in park and check where the selector is underneath

As a home mechanic there is only one thing you can easily do, check the fluid level in the trans and change it if it is dark brown or burned smelling

I assume the car is automatic transmission ? Can you select a lower gear manually using the selector ? Also with the engine running, parking brake firmly applied and the car in Drive, check the automatic transmission fluid is at the correct level. The dipstick is not present on some models however, which is a pain, and would require a dealer visit. If the stick IS present, its on the left side rear when viewed from the front of the car, make sure the fluid is between the two marks.
If your cars is manual/stick shift and it drives in reverse normally, but not in any forward gears then you have a selector issue or internal gearbox failure.

The D selector with the line through it means the transmission range selector switch (also called the nuetral safety switch) is bad. You will also notice that you are getting horrible fuel mileage. If you have less than 36K miles, you may be able to get the dealer to replace it under warranty. Most likely, they will attempt to charge you between $200-$300 for the repair. Go to oemsuzukiparts.com, look up "transmission range selector" in the mechanical section, and buy the part for about $35. It is a simple and easy fix--the sensor is located right underneath the radiator hose on the transmission. Two bolts and a clip hold the thing together, just make sure the car is cold--this car gets really hot under the hood!

There is a tiny sensor on the transmission stick, it is miss-reading the position of the of the transmission stick. You really dont need to worry about it. Good luck

It is possible that the shift linkage is out of adjustment and is going into neutral and not making it to Reverse, try moving the gear selector slowly from park, through reverse to Neutral, and see if it will go into reverse somwhere in between. If this does not work ,you may have Reverse gear failure, a common problem with explorer/ranger transmissions. unfortunatly it requires rebuilding the transmission

The transmission range (TR) switch is part of the park/neutral position (PNP) and backup lamp switch assembly, which is externally mounted on the transmission manual shaft. The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The powertrain control module (PCM) supplies ignition voltage to each switch circuit. As the gear range selector lever is moved, the state of each switch may change, causing the circuit to open or close. An open circuit or switch indicates a high voltage signal. A closed circuit or switch indicates a low voltage signal. The PCM detects the selected gear range by deciphering the combination of the voltage signals. One of these circuits it what is causing your problem but I hope this helps you understand some.