Board the train from Hyderabad Deccan (HYB) to Villupuram Junction (VM). Take train number 22694, which is the Sukanya Express, departure around 9:15 AM (check exact for 2025), journey approx. 14-15 hours overnight.
Relax on the train, enjoy meals available on board or bring packed lunch. This overnight journey will take you almost to Villupuram, then a short taxi or bus to Pondicherry.