Hello Kok Hoo,
Just for further analysis could you upload your: /var/tmp/hdb_TDB_hdblcm_add_hosts_2016-05-30_06.27.42/hdbmodify_addhosts.log.
The reason I asked your RHEL version was I had a problem on RHEL6.6 which meant I also had to do it with hdbaddhost as opposed to hdblcm and I also had no luck getting it to work with saphostagent.
As already suggested by Williams please execute hdbaddhost on the host where you want to install the worker node.
Let us know how you get on.
KR,
Amerjit