Hidden tiles are 8899s.
So the hand is 11m123p77788899s. Waits are 1m, 6s, 9s.
Ron on 1m is a reach-only hand. 50 fu 1 han, 1600 points.
Ron on 6s is reach, pinfu, iipeikou. Let's break it apart.
11m (pair) 123p 789s 789s 78s 6s (the winning tile).
Iipeikou because of the double sequence, 778899s. Pinfu because it's all sequences, non-value pair, double-sided wait. 30 fu 3 han, 3900 points.
Ron on 9s is the highest-scoring possibility.
11m (pair) 123p 789s 789s 78s 9s (the winning tile).
It's the same idea, but winning off 9s makes this junchan, chanta's big brother. All tiles are sets including a terminal, no inside tiles or honors. Reach, pinfu, iipeiko, junchan make six han, which is 12,000 points. Haneman.
If you drew this you could call it san ankou (three concealed triples), but that would be a lower-scoring hand and we only count the highest-scoring possbility. If you drew 1m, then yes, reach, tsumo, san ankou. Mangan (8000).
The tiles can take all kinds of interesting shapes.