What would be the next move?
First, let's list all the possibilities for the 3x3 box in the middle of the left edge:
Now, for the deductions:
Observed the four green cells. In all these cells, only (1, 5, 8, 9) are the possible numbers. Since there are four green cells and four numbers to share, each cell will have one of (1, 5, 8, 9). Therefore no other cell in this box can use any of (1, 5, 8, 9). We can remove those numbers from each other cell's candidates.
That gives us:
It should now be clear that:
R4C8 must be 6, there are no other possibilities.
Hopefully that's enough for a "next move"