I'm gonna warn you ahead of time. You're gonna get a bunch of answers like "we can't tell you that, consult an engineer". The problem is liability. Most of the people here don't want it on them if your tank goes through the floor.
That being said, I don't mind being liable, and will try to help best I can. This can take some basic knowledge of construction and engineering, but it is not Chinese rocket arithmetic as some would make it seem. A lot of common sense stuff imo, which unfortunately many people lack.
Tell us more about your floor. Is it ground floor, 2nd floor? What type of construction? Solid lumber or engineered? Post some pics of where the tank is going and even better some pics of the floor from underneath if you can.
200 gallons is not a whole lot in terms of stressing your floor ime, but its not a little either. Typical rules of thumb when placing big tanks is put them up against a load bearing wall and have the weight of the tank distributed evenly amongst as many floor joists as possible. If at all possible, avoid these issues altogether and put the tank on a solid foundation like a cement slab on your ground floor or basement.
It's a good idea to have a quality level board handy when setting up big tanks. When filling the tank constantly check to see your tank is not pitching forward or back, side to side. If your tank stays right where it was before you filled it thats a good indication your floor is sturdy.