According to the X-Men wikia, Magneto has a variety of powers including:
the superhuman power to channel, manipulate, and generate magnetic fields that exist naturally or artificially
Is there a range on this power? If the range is large or unlimited, is he able to manipulate magnetic fields across large distances at a speed faster than light? For instance, if his target is one light year away, can he affect that target instantaneously or will it take a minimum of a year to affect it?