Rule 2
Section 11. Duties of Shot-Clock Operator
The shot-clock operator shall:
Art. 6. Stop the timing device and reset it:
d. When a try for goal strikes the ring or flange and then possession is gained by either team;
I'd venture to say most officials would judge this to be a try and have the shot clock reset.
Note that this is different than the NBA rule which says that the shot clock is reset anytime a ball from the playing area strikes the rim of the team that's in possession of the ball.