One Zone Per Floor.
1200 sq meters is 12,917 square foot and the maximum you can have on one floor is 52,000 sq ft.
I am assuming with four floors you have a standpipe with sprinklers supplied from the standpipe.
It is possible to sprinkler the entire building, 12,917 x 4 is less than your 52,000 sq ft maximum but be careful with the local fire official.