Yes, it's a good idea to start using a BCAA supplement when you are cutting. This is because when you are cutting, you will be in a caloric deficit each day.
When you are in a caloric deficit, it's possible to lose muscle mass because you're eating less. This can be prevented by eating more protein and adding in high-quality branched-chain amino acids.
Consider stacking them with a fat burner to burn more calories during your cut.