I could not see a monitor for netty. Dynatrace appear to have the ability.
https://www.dynatrace.com/technologies/java-monitoring/ne...
NeoLoad does not embed a Netty monitoring. I would suggest you to post an idea on our community web site.
But looking at that Dynatrace URL, it seems that yo can monitor it using JMX protocol. There's a generic JMX monitor available in NeoLoad. You could use it to gather the necessary information from Netty.