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:)