If you mean pushing the clutch pedal has no effect on the tractor disengaging, then you either way out of adjustment or you might have a stuck clutch disc. This oftens happens when a tractor sits up unused for a period of time. There are several posts on here deal with unsticking one, if that is what you figure happened.
Basically the best way to unstick it is with a load subjected to the tactor with the clutch disengaged. Plowing, discing, and most other ground engaging usually works. Sometimes playing tug of war with anothe vehicle will do it. There are also oil/chemical means but most concern me as contaminating the porus clutch disc can become a problem.
I personally prefer the tug of war, provided you have another larger tractor to play with, especially if it is hydrostatic.
A shock load usually works best, but be careful to not tear up your driveline.
David from jax