Hi Rohit,
Unfortunately there is not a simple way of getting the number of available agents on a Hipath ProCenter system.
If you are not updating the agents every status on a supporting database application and track the agents that are available, then you need to loop for every agent and check their status
You can check
http://www.kodyaz.com/articles/article.aspx?articleid=27 and
http://www.kodyaz.com/articles/article.aspx?articleid=32 fora agent related Hipath Procenter SDK codes