Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Chennai (83% of total searches to Tamil Nadu). The next most popular destinations are Mahabalipuram (6%) and Coimbatore (5%). Searches for hotels in Ooty (5%) are also popular.
KAYAK users have found double rooms in Tamil Nadu for as cheap as $9 (Kodaikanal) in the last 3 days. The average price is $75.