Best places to visit in Pondicherry in one day are:
Park Monument ( Aayi Mandapam )
French War Memorial
Manakula Vinayagar Temple
Bharati Government Park
Pondicherry Botanical Garden
Rock Beach, Ousteri Lake, VaradarajaPerumal Temple etc. Tourists in Pondicherry can also indulge in various water activities like surfing, scuba diving etc. if they are seeking an adrenaline rush. Aurobindo Ashram and Auroville.