A breaker can fail in this position. That is the "Tripped" position.
I would recommend you get a fully qualified electrician to check it out!!.
If you must proceed, 1st, be sure to remove the power feeding that breaker by operating the isolation device to the "Off" position and locking out the isolation device correctly . Then, disconnect all load wires or bars. 2nd, operate the the breaker handle to the full off position and it should latch or remain in the full off position. If it does remain in the full off position without "springing" back to the neutral position, then, you have most likely have successfully "Reset" the breaker. 3rd, with the power that feeds that breaker still "off" or "de-energized", see if the handle can be moved to the full on position and remain in that position. If it does, then the breaker "probably" is still functional. 4th, Verify all load wires or bars are still disconnected. 5th, with the load wires or bars disconnected and using the proper safety equipment, Re-energize the power feed that is going to that breaker. If the breaker remains in the "On" position, it is probably "Ok".
If any of the steps outlined fail, then the breaker "probably" needs replacing.
Also, test the load and wiring to determine why the breaker tripped in the beginning.