Hi Nirupama,
Regarding the text to speech system for Indic languages, there is a GPL-ed application named dhvani. You can see more details from
http://dhvani.sourceforge.net. It currently supports 10 Indian languages. It is designed to incorporate the linguistic rules of Indian languages to TTS. Even though it is not matured as Espeak or Festival, you can try that and contribute to it.
Currently I am working to integrate it to Speech-Dispatcher and there by to Orca. Contact me if you are interested in contributing to Dhvani project.
Thanks
Santhosh Thottingal