Tea tree oil vs vitamin e vs vitamin c. which one is best for acne scarring?

Depends how you use : I'm guessing you're asking about topical application of all of those things. First i would consider making sure that you're taking some supplements internally, such as omegas, vitamin d, and beta carotene, they help heal skin from inside out. Tea tree oil will help heal infected skin. Vitamin e moisturizes skin, and vitamin c helps add antioxidants to skin, which may reduce scarring.