Is it possible to have a diamond set in ring stamped nf925?

No, it is not possible to have a diamond set in a ring stamped nf925. Diamonds are extremely hard gemstones, and setting a diamond in a ring requires that the ring is made of a hard metal, such as platinum, gold, or titanium, to ensure that the diamond remains securely set in the ring. The nf925 stamp on a ring indicates that the ring is made of sterling silver, which is not a suitable metal for setting diamonds, as it is too soft and could easily break or wear out over time.