Hey Dude,
The maximum number of connects that can be established at the same time to an NFS Server will also depend upon the number of server processes that are running for the nfs deamon (nfds) on the server .
If you expect high number of machines connecting to this server you could increase the no. nfsd processes by simply making an entry in the rc file or just manually restarting nfsd to try with.
nfsd -n 6 <no. of processes of the deamon to start>
It will also depend on the harware configuration and load on the nfs server and connectivity with the network.
Hope This would Help
.... Nitin ....
I Blog at nitinb.blogspot.com