Pondicherry is well connected by Road with all major cities in Tamil Nadu, Kerala, Karanataka and Andra Predesh. If you’re traveling from Chennai to Pondicherry, there are buses which depart from CMBT koyambedu Bus Terminus for every 15 - 30 minutes.
From Chennai :
From Bangalore :
Pondicherry is about 250 Kms from Bangalore. Drive down Hosur road till Krishnagiri, take a left off the main highway (roadsigns mark the route) and then join the National Highway to Pondicherry. Towns enroute while coming from Bangalore to Pondicherry are Uttanagarai, Chengam, Tiruvanamalai, Tindivanam.
Gingee fort, is also on the way and a worth spending some time. It is a Archealogical survey of India (ASI)Heritage site!! The total travel time should be about 5-6 hours. Do pack some food or snacks for the way as there are no good restaurants enroute.