NTA latest version is 4.1.1 (not 4.3).
The pre-policy and post-policy charts are good for understanding how QoS models class data. pre-policy means data arriving to the device and post-policy data where QoS applied limitation/priority. you should compare side by side pre and post policy and see if QoS limits the shape of the incoming traffic (that means QoS limitation was applied). you can also see distribution of traffic into QoS classes which helps you to understand how you have it configured and if you need to move some traffic into some specific class and apply policy. If you haven't you may found How can I monitor QoS policing and shaping? interesting too.
I have problem in CBQOS, like some of the devices are not responding to CBQOS in NTA summary .
LAST RECEIVED NETFLOW column is getting updated but LAST RECEIVED CBQoS is showing as never.
Even i observed that in a single router we are monitoring 2 interfaces.
1 of the interface is getting update with CBQoS but the other interface is showing as never. pls check & suggest.
Are you sure you have enabled CBQoS for all interfaces (which you wish to monitor) in NTA's Manage sources? Do you have QoS configuration assigned to these interfaces?