NFS VS Auto Mount problem

Dear All,
Struck with a peculiar problem

a) /opt/a is auto mounted to /home/a for User:a
When the User logs in to the server his home directory is getting mounted from the autofs i.e /home/a (/opt/a), Instead is has to mount the User home dir from NIS which is /home/a (from NIS).

Checked all auto_home & auto_master entries and provided all the desired entries to get the suitable result (mounting the user home dir from NIS).

Please provide me with the suitable solution to resolve this issue.

Thanks in advance

Did you also check /etc/nsswitch.conf?

Please rephrase that to be more intelligible and post configuration and commands that would help understanding what the problem is.