Assuming you have single adjustables your goal is to set the rebound to control the energy stored in the springs.
If the car feels to floppy, floatly or unstable during braking in the rear, you are not controlling the springs and you should increase the rebound dampening.
If the rear end feels like it is ratcheting down, sudden transitional oversteer, rear wheel hop or skitterish reduce the rear rebound dampening. You are over controlling the springs.
Specific settings, numbers or turns won’t help you, every tire, surface, wheel rate, roll center, roll bars, track width… are different and will result in your car handling, balance differently from every one else.
Make careful notes and try to start off with as minimal amount of rebound as possible and you feel comfortable with, 3/4 turn, If you feel the car is unstable in braking or too floaty increase the rebound . Most drives will feel safer and more comfortable with excessive rebound setting but over controlling the springs will not allow the springs time to relax between transitions. The car will feel predictable and secure but will likely be slow to react and slow on the time sheet.
Concentrate on what your feeling and make big changes in settings to begin with. When your confident in what you feel, fine tune your adjustments.