Ansible Multiple Conditions Using when ons Single Task.md

There are a lot of ways on doing it. One of it is as follows:

1tasks:
2  - name: "shut down CentOS 6 and Debian 7 systems"
3    command: /sbin/shutdown -t now
4    when: (ansible_facts['distribution'] == "CentOS" and ansible_facts['distribution_major_version'] == "6") or
5          (ansible_facts['distribution'] == "Debian" and ansible_facts['distribution_major_version'] == "7")

Read further in Ansible Official Docs.