How LM Cloud identifies new EC2 instance in AWS account? Is Netscan using cloud Watch API to query the new resources?

@Naveenkumar - That is correct. A LogicMonitor owned collector will make API calls to your AWS account for discovery of new EC2 instances.

Here is a LogicMonitor support article that covers some of the design and setup.
https://www.logicmonitor.com/support/aws-monitoring-setup