How do I calibrate a topcon laser ? - Topcon Rotating Builders Red beam Laser Level RL-VH4DR-GC

There are detailed instructions in your users manual on how to check and adjust your Topcon laser. You'll need a tripod, 2 vertical surfaces about 50 meters apart and your laser receiver. It's done by marking positions of the beams, on the different surfaces and then adjusting your laser position to the center of the different positions.
The procedure is different for different models, but i have attached some pictures from the manual for the RL-VH4 series.

Find a place closest to you that calibrates these instruments and send it there