My mothers 2000 honda civic will not drive in reverse or forward position?

Make sure the shift cable is working properly at the shifter and the transmission if you have good action then check the transmission oil (make sure you use honda synthetic oil or the car will shift hard) if they get low on oil they will send the shavings through the shift solenoids you can try to drain the transmission oil with the drain plug. (there is not a serviceable transmission filter )take the solenoids off and clean the screen in them but more then likely you will have to dissasemble the trans. The trick to these transmissions is never let them run low on oil or they get contaminated with the clutch shavings that go into the shift solenoids.they are famous for leaking axle seals if you get it working check your axle seals and replace them if they are leaking