Which Tulsi type sells best and where is the market for Tulsi leaf or oil?

For commercial Tulsi, the type matters because the buyer decides what they want. Some herbal companies buy dried leaf or whole herb for Ayurvedic products, while others want the essential oil distilled from specific oil rich types like the eugenol rich varieties. So first find your buyer and ask exactly what they want, dried leaf, whole herb or oil, and the variety or chemotype they prefer, then grow to match. There is genuine demand from Ayurvedic and herbal firms, but it is buyer driven with no fixed mandi, and prices vary by form and quality. Tulsi is a relatively short, hardy crop, which lowers risk, but you still need a confirmed buyer or a distillation tie up before planting at scale. Verify the buyer and price in writing first.