chaitanyamanot, first up, the rules. No posting your email address in your posts. Secondly, use proper english. No cyberchat style posts.
I have removed the email address from your post. See the
rules for more.
Before downloading/installing, find out more about unix/Linux from the internet. You can search on google. There are also several distributions of Linux that are freely available for download.
Ubuntu,
Debian,
Suse,
Redhat Fedora.
You can go to these sites and see what Linux is all about.
If you are interested in 'unix', go for
OpenSolaris,
FreeBSD.
Remember, google is your best source for all information. If you face any specific problems while installing/working with Linux/unix, you can post those questions on these forums (fora!).
Also, the various operating systems here are not the only ones available. There are many more...