"Ponni Best Diamond" is likely a name used for a specific brand or variety of Ponni rice. Based on the available information, it's a type of premium-quality rice, often sourced from South India, that is known for its non-sticky texture, mild flavor, and use in a variety of dishes. The word "Diamond" in the name, such as "Supreme Diamond Ponni Rice" or "Diamond Brand Akshaya Ponni Rice," appears to be a branding term used to indicate a high-quality or premium version of the product.