Several Drupal versions configuration

We are going to organise our site into several subdomains the following way: https://domain.com – Drupal 7https://subdomain1.domain.com – Drupal 7https://subdomain2.domain.com – Drupal 6https://subdomain3.domain.com – Drupal 8 The question is will it work or this configuration is not possible? The site will be hosted at https://www.a2hosting.com/web-hosting/compare[…]