Balaji,
I suggest that you use the 30 -day free trial offer from SAP to setup a SDN account to have free cloud server HANA DB access using the below link. The link works for 30 day free trial and also permanent access.
http://scn.sap.com/community/developer-center/hana
After 30 days, you can setup your own cloud AWS instance and practise. It is affordable and you pay as you go. I own one and it is affordable. Let me know if you need additional info.
Hope this helps.
Rama