Question: what is the difference between tire size 185 and 195?
Answer: Your tire 185/65R15 is narrower, 195/65R15 is fatter, only 10 mm wider, their diameters are the same. Sure, you can use them all, because they fit rim 15 inches in diameter (If it is measured the ID of the rim, it is 15″ but the OD is 16 and 1/2 inches.).