When you going a group, you have full control of it in Viber. If you invite other persons, the group will stay active for as long the users will remain in the group regardless if you leave or not, but leaving doesn't delete the group. When you leave, the ownership is transferred to the next user. For a group to be deleted, every user needs to leave. The last one will be notified that the group will be disbanded. It also doesn't matter if you use Viber on mobile or PC because the behavior will be the same.
