Each inspection station used to have a machine that checked how good your brakes were before they would give you a sticker. But, I have not seen that done in many years. But Orleans Parish has it's own sticker that you have to have if you live in Orleans Parish and you can only get it in Orleans Parish.
On a side note, the way you used to get one if your car would otherwise fail was you left a $20 bill on the seat of your car while they inspected it as a "tip". But, as of like 20 years ago Orleans lets you get them at private inspection places and they don't normally require bribes.