Range, gamut, reach, radius, compass, sweep, scope, orbit, horizon, ken, purview can denote the extent that lies within the powers of something to cover, grasp, control, or traverse.
Range is the general term indicating the extent of one’s perception or the extent of powers, capacities, or possibilities.
Gamut suggests a graduated series running from one possible extreme to another.
Reach suggests an extent of perception, knowledge, ability, or activity attained to or experienced by or as if by stretching out.
Radius suggests a usually circular area (as of activity) implied by a known or determined center.
Compass implies an extent, sometimes more limited than that suggested by range, of perception, knowledge, or activity; it is likely to connote a bounding circumference.
Sweep suggests extent, often circular or arc-shaped, of motion or activity, which latter notion it more strongly suggests than the preceding terms.
Scope is applicable to an area of activity, an area predetermined and limited, but an area of free choice within the set limits.
Orbit suggests a range of activity or influence, often circumscribed and bounded, within which forces work toward accustoming, integrating, or absorbing.
Horizon suggests an area, perhaps arc-shaped or semicircular, of knowledge, interest, perception; it may suggest the new or the potential or envisioned.
Ken tends to apply to personal or individual range of perception or cognizance.
Purview may indicate either range of perception or knowledge or range of authority or competence.