I have lot of ance scars that are caused even after letting it break naturally. How can I reduce the scars? They are on my back nd face

Wound care. Keeping wounds clean and free of infection while avoiding sun exposure and cigarette smoking are your best options for minimizing scars. Cleansing with a mild soap such as non-medicated cetaphil and non-comedogenic moisturizers are the mainstay of therapy. Silicone gels may help. Allium cepa is controversial as is vitamin e, cocoa butter, cocoanut oil, vitamin k, green tea extract, aloe vera, etc.
Acne scarring. First and foremost, I would recommend you seek out a dermatologist to help you get your acne under control. This will help you reduce the number of new lesions. And if you reduce the number of new lesions you will reduce scarring. Once this is under control then you could consider cosmetic procedures to help reduce the scars that remain. I hope that is a good start for you. Good luck.