I own a 2001 Audi A6 and the car turns on and I hit the break to put it in drive and it goes in to drive but won't move forward or reverse. Can anyone tell me what the problem is

when you engage the trany does it allow you to push the car or does it remain immobile and in park? you could jsut be low on trany fluid or your shifter linkage has snaped or broken.

Yeah it let's me roll the car when I engage the tranny

thats unfortunate.... you need a new trany .. Try this. Jack your car up so the front wheels are off the ground. grab an axel and try pulling it out and back in. or move it around. if its loose it might simply be a bar bearing. but there is also something else yopu can check for. check the fluid levels of your cars trany. remove the plug in the front dif and stick your finger in. if you get trany fluid on your finger its fine. move to the rear plgu in the main part of hte trany and do the same but be careful if it is full it may come out since the tranny won't move. if you get nothing it probly jsut needs fluid. Check for leaks the rear trany seal sends to leak after a while.