Did you know that you can auto-assign ownership for requests based on pre-defined conditions? Yes, with Request Assignment Rules you can perfectly route your incoming requests to the appropriate department and further assign ownership to it once moved. Besides incoming requests, you can set an assignment rule to be applied while updating a request too. Further you can add multiple assignment targets to a rule to get the maximum benefit out of it.
Read further to learn how to go about it.
To add a new request assignment rule, follow the steps given below:
If you have more than one department in Zoho Support, you can choose to move requests between departments based on pre-defined criteria and further assign ownership to a request once moved to the new department. 
While assigning requests to agents from the drop-down, you can view only those who are active and confirmed in a department. So kindly confirm if John is an active agent in the chosen department. You can check this by going to Setup >> Organization Settings. Click on the related department to check whether John belongs to it.
Unlike Workflow rules, Request Assignment rules are cross department which allows you to move requests from one department to another based on pre-defined criteria and further assign a owner in the moved department. Also, more than one Workflow rule can be applied to a request when matched with a pre-defined criteria. Whereas in Request Assignment rules only the first target matching the criteria would be applied and all else would cease to trigger.
When a new request is received or an existing is edited, Request Assignment rules are the first to be triggered when matched with criteria. Following Request Assignment Rules, the order of execution moves to Workflows, SLAs and then Notification Rules.
Request Assignment rules are available only for Enterprise & Professional customers in Zoho Support. Enterprise users are allowed to create a maximum of 20 assignment rules, whereas Professional users can create 10. Each rule can be associated with a maximum of 5 targets.
You can deactivate or dis-associate an agent from a department. But the assignment rules associated with the agent would cease to work from thereon. You can always revisit the assignment rules to edit/delete the targets which may not be required anymore.
You are not allowed to disable a department when it is associated with targets in Request Assignment rule(s). Revisit your assignment rules to edit/delete the targets containing the department name from the 'Request coming to' or the 'Move Request to' fields. Following this, you would be able to successfully disable the intended department.
You can track the activities on a request by accessing its History. Though a request is moved between departments via Request Assignment rules, the activities happened on it is always archived under its history.
To deactivate an individual assignment rule, click on the rule name. In the assignment rule page, uncheck the Active checkbox to make the rule inactive. Also if you want to disable the assignment rules all at once, click Disable Rule Execution in the Request Assignment Rules page.
Assignment rules are triggered when a request is created or updated and being received across all channels in Zoho Support. Besides these, assignment rules are also applied when a request is split or merged.