Please see the below points:
-> After the agent installation the Endpoint should be in network for atleast some minimum time for it to get the same reflected in console.
-> U should have enough license to accomodate all the agents to report to console
->Assuming you have installed all the agents with the same package, make sure that the Endpoint server IP address you are mentioning during installation is correct
-> Finally try restarting the services in the Endpoint server and check,if still the issue persists raise a case with Symantec support.