After fixing this, created coreos cluster with 2 master's and 1 minion:-
minion successfully registered with master nodes.

ubuntu@ubuntubase:/opt/stack/magnum$ magnum cluster-show k8s-cluster
+---------------------+------------------------------------------------------------+
| Property            | Value                                                      |
+---------------------+------------------------------------------------------------+
| status              | CREATE_COMPLETE                                            |
| cluster_template_id | cab7d7c5-c43b-4c92-91b8-4392f6dab19f                       |
| uuid                | d1a1bf9d-fce6-4717-8203-de59faefe9b0                       |
| stack_id            | 6b83c620-a1df-4622-95d4-36ac8877188e                       |
| status_reason       | Stack CREATE completed successfully                        |
| created_at          | 2016-10-05T04:37:02+00:00                                  |
| name                | k8s-cluster                                                |
| updated_at          | 2016-10-05T05:05:50+00:00                                  |
| discovery_url       | https://discovery.etcd.io/9ccef8c176df28aef64204c6fca5b138 |
| api_address         | https://172.18.33.11:6443                                  |
| coe_version         | v1.2.0                                                     |
| master_addresses    | ['172.18.33.9', '172.18.33.13']                            |
| create_timeout      | 240                                                        |
| node_addresses      | ['172.18.33.4']                                            |
| master_count        | 2                                                          |
| container_version   | 1.11.2                                                     |
| node_count          | 1                                                          |
+---------------------+------------------------------------------------------------+

ubuntu@ubuntubase:~$ kubernetes/platforms/linux/amd64/kubectl get nodes 
NAME        STATUS                     AGE
10.0.0.13   Ready                      18m
10.0.0.3    Ready,SchedulingDisabled   30m
10.0.0.8    Ready,SchedulingDisabled   32m

ubuntu@ubuntubase:~$ neutron floatingip-list
+--------------------------------------+------------------+---------------------+--------------------------------------+
| id                                   | fixed_ip_address | floating_ip_address | port_id                              |
+--------------------------------------+------------------+---------------------+--------------------------------------+
| 0d00cb03-d95a-40df-bc52-3e6d5a5c62d8 | 10.0.0.8         | 172.18.33.9         | ea8b9dc7-2f17-4729-aed9-5a2d7f26f0cc |
| 452f13a4-c4b3-40c2-bc0e-7c94ab360655 | 10.0.0.3         | 172.18.33.13        | 9ebec5a4-a0d1-466c-a13c-f65486c3361e |
| 61c8db7d-1cae-4fad-a24a-1430cdc81c3a | 10.0.0.13        | 172.18.33.4         | 70b9743a-a1ae-4f5c-a111-26f9cc52890c |
| 9b06d2b4-b9ae-43b4-b08c-9963f4122d62 | 10.0.0.9         | 172.18.33.11        | 6f5983b4-5435-4351-a562-362c5ee06029 |
+--------------------------------------+------------------+---------------------+--------------------------------------+