When you receive your camera, we already adjusted the focus for the camera to be operational in a general surveillance scenario. For your IN-6001 HD this means, that they give you a sharp image for distances between 5 and 10m. If you need a different focus distance, just turn the camera lense clockwise or counterclockwise, until you have your scene in focus.
Fig. 1/2 Connect the camera to the power supply and the network cable. Open the web interface and turn the lense until you can see a clear and sharp picture.