Definitely not. For full of south India is scorching all through summer. Though it’s a beach spot where you can view jaw dropping sunsets, feel cool air still its not ideal to visit Pondicherry now. Best season is after September and excellent season is from end of December just after the rains.
May should be a best time to visit hill stations, this year it's very hot specially in the coastal places, as there's sea nearby it wouldn't be a good idea to visit in may. Winters will be the best months.