Kindle has its own file format. azw.
It supports mobi too.
But it does not support Tamil.
The Tamil letters will look old and splitted.
To read Tamil in Kindle, we have to create 6 inch PDF files.
Documented here on the process.
http://onroads.wordpress.com/2012/11/23/how-to-read-tamil-books-in-kindle-ebook-reader/
We can print to 6 inch PDF directly from Firefox too.
Check the point 8, for changes to do in Firefox.
http://goinggnu.wordpress.com/2014/02/01/how-to-create-an-ebook-for-free-tamil-ebooks-com/
Check the 6 Inch PDF files from FreeTamilEbooks.com too.
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Regards,
T.Shrinivasan
My Life with GNU/Linux : http://goinggnu.wordpress.com
Free E-Magazine on Free Open Source Software in Tamil : http://kaniyam.com
Get CollabNet Subversion Edge : http://www.collab.net/svnedge