Reflection of light-basics

A pole of height 4m is kept in front of a vertical plane mirror of length 2 m . The lower end of the mirror is at a height of 6m from the ground. The horizontal distance between the mirror and the pole is 2 m . Upto what minimum and maximum heights a man can see the image of top of the pole at a distance of 4 m standing on the same horizontal line which is passing through the pole and the horizontal point below the mirror ?

Please explain with a diagram