RSS feed is by default enabled in MonoX. For example, on our demo MonOX site, it can be accessed at the following URL:
http://monox.mono-software.com/blog/posts/MonoX/?MonoXRssFeed=MonoX
RSS links are embedded in the header of the page, with support for RSS "autodscover" feature. You can find all embedded links easily (for example, on IE 9 click Tools - Feed discovery).

hi denis.
thanks for helping me..denis plzz tell me the rss feed url and where that page is stored in source code..tell me step by step what steps i have to follow to use the feature of rss feeds..

There is no static RSS page in the code. RSS feed is dynamically generated by Web parts that implement the IRssWebPart interface. The actual generation process takes place in the MonoSoftware.MonoX.RssEngine.RssEngine class.
Could you let me know what exactly you nmeed to do?

thnx denis..i have succeded in my task..now i am able to use the rss feeds.
2 more query denis..can rss feeds be applied for particular post or blog and can i apply rss feeds for discussions and if i can what will be the url plzz help me...

By default, an RSS feed is present in parts that display a list of changing items (blog posts, discussion topics, etc.), and not on the individual items (single blog post). You can always find such links by looking in the header of the page and searching for a link (or multiple links) of the following format

For example, this page holds a RSS feed containing messages that we exchanged in this topic and that you could subscribe to.

thnku so much denis..can u help me plzz if i posted a post on blog and that post can be seen only by my friends not by any other person..how can i do this..tell me plzz..

Not by default. It could be implemented with a few lines of custom code, where you could use the GetFriends() method in the MonoSoftware.MonoX.Repositories.FriendRepository by passing it the user ID of the blog post author, and than checking if the currently active user (SecurityUtility.GetUserId()) is present in the it - if not, the request woule be redirected to your custom message page, informing the user that it hasn't got the access to that particular post.

thnx denis for guiding me but 1 more query denis...privacy box which is used in user profile page to just show the status according to the option selected like private,public or friends...
denis plzz help me how can i use it with blogs that when i posts the blog it will just shown to the option selected from the privacy box i.e. only to friends or any other option selected...

This is a more complicated scenario, in which you would have to change the structure of the BlogPost table to include the PrivacyLevelId (a foreign key linked to the primary key in the PrivacyLevel table). Let me know if you have the source code of MonoX, so we could guide you through the process.
I will put this topic on a "todo" list for our future tutorial blog posts.