Please tell me, could i increase my height up to 3-4inches?

Not much to offer: I recall some research in the scandinavian countries where the upper leg bones (femurs) were cut. Rods were placed through the skin ; bones ; attached to a special stretching device. Bone grafts were placed ; if it didn't fail the person could gain a few inches. Seems a bit drastic, ; i know of no one doing it now. If you are 38 ; growth sites in bone are sealed, you are at your final height.