If reports are generated in Freshdesk, how can i select who can view them?

You can give the agent only "Agent" Role so that he/she will not have access to the Reports tab. You can do this from Admin--> Agents--> Edit the Agent--> Scope and Role. Or if you are in the Estate or Forest plan you can create a custom role from Admin--> Roles in which the agent cannot view the Reports section and assign that role to that specific agent.