Hi Lori,
It is my belief that a 185 tire will fit as the minimum size on a 6.5 inch rim. That same rim will also be a little more ideal for a 195 or 205 tire.
The original tire size for our cars is 185HR14. They are getting increasingly more difficult to find especially if you are not willing to spend what many consider a lot of money. If white wall is your thing then your choice is even more limited. More common is a P195 tire, and many people are running 205/70 tires as well.
So it looks like your rims will pretty much cover all the bases of tire availability.