We had an issue where in cPanel server where we had our rDNS settings

were no working. On editing and saving the file from WHM , Rdns worked

Found the issue was due to corrupted named.conf

Below are the steps undertaken to rebuild named.conf

mv /etc/named.conf /etc/named.conf.bak

/usr/local/cpanel/scripts/rebuilddnsconfig

/scripts/restartsrv_named

Now rdns and other records are working fine:)