Hey Santoshw85,
The plugin will support as many feeds (using different Facebook page/group accounts) as you wish on a single site. For purposes of your visitor’s experience in page loading time however it is recommended not to put more than a few feeds on a single site page.
This of course is dependent upon how many posts you are downloading for each feed. If you were only downloading 4 posts from 4 different Facebook accounts then this is a total of 16 posts being downloaded from Facebook which is not a problem.
However if you set the same site page up with the same four Facebook accounts to be displayed and you set your plugin settings to download 100 posts per feed (the maximum Facebook will send per API request) then you are waiting for 400 posts to be downloaded which will significantly affect the page loading time your visitor will experience.
A feed does not make an API call for posts from Facebook until the actual site page containing the feed is visited so putting a single feed on a page and having 500 pages (each with a different feed source) will not be a problem.
To set each feed up differently you would need to use the appropriate shortcode option to identify the Facebook account source. For instance, if you wanted to display a feed containing 4 posts from CBS and another feed containing 7 posts from NBC then your shortcodes for each feed would look like this:
[custom-facebook-feed id=cbs num=4]
[custom-facebook-feed id=nbc num=7]