correct csv format

server1
server2
server3
PermitEmptyPasswords no
PermitEmptyPasswords no
PermitEmptyPasswords no
Found
Not Found
Not Found
  
*But I want output in this format-:*

server1, PermitEmptyPasswords no , Found
server2, PermitEmptyPasswords no , Not Found
server3, PermitEmptyPasswords no , Not Found

Try this

    - shell: echo
             "{{ lines|map('extract', output)|list|join(',') }}"
             >> file_output.csv
      loop: "{{ range(0, len|int)|list }}"
      vars:
        step: 3
        len: "{{ output|length / step }}"
        lines: "{{ range(item, output|length, step)|list }}"

This is probably the right time you post the "output".

You've already said

     - name: list output to CSV
       shell: echo "{{ item }}" >> file_output.csv
       delegate_to: 127.0.0.1
       with_items: "{{ output }}"

*the output of csv file-:*

server1
server2
server3
PermitEmptyPasswords no
PermitEmptyPasswords no
PermitEmptyPasswords no
Found
Not Found
Not Found

I guessed the variable "output" is a list

    output:
      - server1
      - server2
      - server3
      - PermitEmptyPasswords no
      - PermitEmptyPasswords no
      - PermitEmptyPasswords no
      - Found
      - Not Found
      - Not Found

Is it?