Hi,
Thanks for your reply.I'm not sure about changing the environment variable will change the  Finance::Quote default timezone .
There might be some method like  setCurrency which will take care of the timezone settings
Please suggest me on this
Update :
Yahoo fetches all the asia symbols from his singapore domain. So it returns the value in  GST format. I have used  DateTime module to get the  Asia/Calcutta timezone information.
Thanks,
- Raja