Row 6

Now, we'll follow the same procedure for the 7s.

Again, we have only one possible placement fo the 7 in blocks 3 and 4.

Now we can safely enter those numbers and remove any 7s from the corresponding rows or columns.

And that leaves only one possibility for the 7 in block 6. And it also nails down the 8 in block 3! Now, we're making progress.