Not heard of "red apple vinegar", but maybe you mean apple cider vinegar, which is found at the grocery store, next to the distilled white vinegar.
If buying the popular Heinz brand, check the label closely to make sure you're getting the real deal, "apple cider vinegar", not "apple cider flavored vinegar." This switch is especially common in containers larger than 32 oz., but has been seen in smaller containers, too.
Regards,
Chris