Tyre dealers here have access to the CoC of different cars and check a car's registration number before advising on authorized tyre sizes. To answer your question, I wasn't given a written confirmation. However, the documents of the 16 inch rims I bought state different cars that the rims are suitable for and the corresponding tyre sizes. The sizes mentioned therein are the same as the ones declared suitable by the tyre dealer.
In the case of the Yaris XP9, XP9F the following sizes are acceptable:
195/45R16, 195/50R16, 205/45R16, 215/40R16 and 215/45R16. I went for the 195/50R16. Let's see how this will affect the performance and fuel economy.