Hi Kuldeep,
You can modify the 'ns2' awk script to read/understand the NS3 format.
There is also tracemetrics tool (
http://tracemetrics.net/) that can analyse the trace files but it is based on an earlier ns-3 trace which may have changed since then.
These are based on analysing the trace files. Nevertheless, you can use FlowMonitor and/or the statistics framework within your scenario to calculate those metrics.
Examples available throughout ns-3.
Regards,
K