Land Rover Repair: Is it a Gearbox Problem?, splined shaft, transmission failure

Question
My 1998 range rover goes fine untill one day i could feel annoying niggle when transmission change (Like someone coughing.

Few days ago, i parked my car and when tried to start it, i couldn't. The car is not moving even a single step forward or backward eventhough i could move the selector.

Would you like please helping me in suggesting and diagnosing this?

Answer
If the gear selector moves from park into gear but the vehicle does not move you might have a transmission failure, or you might have failure of the splined shaft between transmission and transfer case.

You could also have a problem with the shift cable but if that were the case the shift lever would feel funny.  If your shifter feels notmal your next step is probably going to be transmission removal.