Combine 2 completely different if statements

Sorry, even after looking at the workbook and reading again your explanation in post#3, I'm still at a loss as to what you require here.

Could you show your expected result and breakdown how you arrive at that result?

BSB

I'm trying to combine it under the S column like this:

=IF(K3="T",M3,0,OR(N3-M3>0,0,N3-M3))

But that doesn't work