I am looking at monitoring the contact centre calls to citrix.
is this something that would be possible using RUM?
I want to be able to tell if a user has had issues with latency or not
Yes you can monitor the contact centre calls using EUM feature. Just go ahead and instrument your application as directed in the doc link below:
Onc eyou start using EUM, you can also use the Browser sesisons to track each user login session details and timing: