Is it advisable to use the hi rib cementing style to correct the whole un level wooden second floor area? It is not level from between 1 to 2 and 3/4 inches in certain areas.
No. Hy-Rib is an exterior industrial product not intended for residential use, and IIRC you'd never cover it completely w/ less than 2 full inches of concrete, adding an incredible amount of weight to your WOODEN structure.
If your floor is that far out of level, that suggests problems in the underlying framing. The best fix is to correct from the bottom up - start in the basement and adjust the 1st floor to level or as near level as possible, then repeat working your way up the house.