When I parent an object with a bone the object moves its place I went to the object tab and parented with a bone. but when I did this, the object rotated and moved. what should I do to fix this? (weirdly when the object moves its place the location which is displayed on the tab that appears when you click 'n' is the same)
You must have parented the object with a bone that is not in Rest pose, so first select your bone in Pose mode and altG, altR, altS to reset its location, rotation and scale.