In our scenario, we took a server which has nfs fileset issue.

Please run the following:

# oslevel -rq
# oslevel -rl 6100-09
# oslevel -sq | head -1
# oslevel -sl 6100-09-03-1415

As mentioned in the first email, you need a baselevel fileset to force overwrite the bos.net.nfs.client fileset using the command:
# install -Facd . bos.net.nfs.client

Baselevel filesets can be found on the ESS website http://www-304.ibm.com/servers/eserver/ess/OpenServlet.wss
If you run into any issues with that please follow the options below:

Registration assistance for ESS (Entitled Software Support):
If you would like to be able to download media in the future, register at this site:
http://www-304.ibm.com/servers/eserver/ess/OpenServlet.wss
If there are any issues with access to the site or need assistance with it, call ESS Registration Assistance: 1-800-446-8989, option 1 … the phone will beep about 6 times and someone will pickup answering as “Customer software support.” They will assist you as needed.
-OR-
3) If there are any issues with downloading, please contact level1@us.ibm.com as the AIX Install Support team is not affiliated with the ESS site.
An alternative for receiving assistance is by clicking the “Feedback” link on the login page at:
http://www-304.ibm.com/servers/eserver/ess/OpenServlet.wss