It depends on the camera technology, and the cable used.
For standard/traditional CCTV (composite video, 1 volt peak-to-peak), and using the most typically used RG59 co-ax cable, then you can go up to a maximum cable length of about 250m.
Heavier cable will allow you to go further.
Other camera/signal technologies may allow you to go further.
Baluns and adapters can also be used to extend the maximum length.