please advise us what needs to be excluded
Nobody can tell you what to exclude.
Backup selection is a business requirement.
or how can i increase the throughput.
You need to find out where the bottleneck is.
First step is to test filesystem read speed on the client. You can use OS methods such as tar or NBU bpbkar method.
How are you backing up the Zone(s)?
From the global zone with local zones shut down or as normal client with NBU client software in local zone?
Have you read through the NBU doc that deals with Solaris virtualization?
See http://www.symantec.com/docs/TECH162994
