Hi Ganesh, it's not possible to use RSS for reply notifications as far as I know, only direct e-mail. W7Forums.com does have RSS feeds for latest threads, either across the whole forums or category specific - but RSS isn't really designed as a notification service.
If you want to subscribe to a thread, make sure that you click the "watch thread" button on the top right corner of the thread page. You can set it up to auto-watch all threads you create or participate in on this page: https://www.w7forums.com/account/preferences
RSS feeds are constantly updating feeds of data that you can subscribe to, to alert you to new content appearing on the internet. For example, a news website would have RSS feeds which link to all of the new articles it adds. This forum has one to alert you to all of the latest threads posted on the site.