That depends on exactly what you are working on and trying to accomplish. Ideally - the chassis would be set up at ride height and body set at the desired position on top of the chassis.
I suspect most people here have
this image in their head based on what you've asked. It's not clear what type of car you're talking about, how much you want to lower the car, why the car is or needs to be so low. Or, what you want to do with it once it's that low.