how many organizations do the member of the IO and NGOs in Cambodia ?

Answer 1

Your question isn't exactly clear. Do you mean how many NGO's or IO's does the country of Cambodia have in it?
Have you contact the Cambodian embassy for this answer, they would definitely know.
Here is a link to a forum discussing Cambodia, if you asked your question on here you'd get a better response:
http://www.cambodiaforum.com/index.php?showtopic=4644

Best wishes to you.