I download [This][1] template and I added a template to (public_html/My_Host/templates) and change the Template from admin panel (Setup->General Settings->Template) but it does not work just six template work I download the template from
[1]: https://colorlib.com/preview/theme/hostspace/
Did you downloaded WHMCS Templates ? (Note:Normal html5 templates never work as whmcs template ).
If yes, you need to upload and extract in "public_html/WHMCS_DIRECTORY/templates" .
Then it will list out in WHMCS "Setup->General Settings->Template" area.