Hi, if it is Solaris 8, there should be a 'vold' daemon running which by itself mounts the CDROM. If it is not getting mounted automatically on /cdrom/cdrom0.
If you want to restart the daemon, you can do
ps -ef | grep vold and kill it. To start it again,
/etc/init.d/volmgt start
In case you have to mount it manually,
mkdir /tmp/cdrom
mount -F hsfs /dev/dsk/c0t6d0s0 /tmp/cdrom (In most solaris bboxes it is on target 6)