Thumbs up to the above post.
To Clarify:
12 immature plants - this includes but is not limited to: sprouted seeds, seedlings, clones, and vegetative plants that have not yet shown signs of sex.
OR
6 mature plants - this would be any six plants showing signs of sex. (in court, any sign of sex will be considered a mature plant, regardless of size)
With great emphasis on the "or" --- There is no stacking.
The most effective cycles depend on your own personal tastes/setup. I would recommend these.
2/2/2 (2 clones, 2 vegging, 2 flowering)
Difficulty: Medium
3/3 (3 vegging, 3 flowering)
Difficulty: Light
6 (Running 12/12 light cycle from clones)
Difficulty: Easy
When it comes to California state law, you're most effective plan of action is to learn how to train your plants... Search for "LST" and/or "SCROG" --- because you're number of plants is limited by state law, these methods will effectively allow you to yield more product per plant.
Hope this helps.