Hi Kabilan,
1.first, you can add a Note Board Web Part on your page.
2.Enable the publishing infrastructure site collection feature
If you do not activate the publishing infrastructure feature, the note board will appear to work, but will not store comments correctly. The note board does not use the correct url for
the page, so the notes stored using the web part, will differ from the notes stored using the Tags and Notes button. See the image below to see what I mean.
Please refer to the following link.
http://donalconlon.wordpress.com/2011/03/02/adding-the-social-note-board-to-a-sharepoint-blog/
Thanks,
Jack