Dear Anil,
If you come to Chennai, you have to again catch a train to Tindivanam and alight and then catch another train to Tiruvannamalai. From T'malai Railway Station, you have to take
an autorickshaw and come to the Asramam.
It is better to catch a bus which takes you directly to Tiruvannamalai from Chennai. But from Chennai Central Railway Station, you have to come to Koyambedu Bus Stand, which is about 12 kms. You can cover by auto. Speak English. Not many understand Hindi in Tamizh Nadu.
If you can afford, you can come directly by taxi up to the Asramam, for which charges would be Rs 2000+ one way.
Arunachala Siva.