As of my last update, finding the best river sand supplier in Chennai typically involves considering various factors such as reliability, quality, adherence to regulations, and customer reviews. Here are some reputed river sand suppliers in Chennai:

1. Civil Bazaar (www.civilbazaar.in): Known for providing quality river sand, they have a reputation for reliability and timely delivery.
2. Murugan Groups (www.murugangroups.in): This supplier is recognized for offering high-quality river sand and other construction materials.

When selecting a supplier, ensure they source their river sand legally and ethically, adhering to environmental regulations. Also, consider factors like price competitiveness, delivery options, and customer service. It’s advisable to check customer reviews or seek recommendations from local contractors or construction companies to gauge the reputation and reliability of a supplier.