Abhay-
There are no set industry standard for any call center metrics. In order to determine what is best for your call center you need to consider the motivation of the caller to establish the target service level, the call type, knowledge base, tools and experience of the representative to determine handle time and wrap-up times, and the appropriate length of the call to meet hte needs of the customer, through quality monitoring, surveys and focus groups with the customers.
I live in Portland and am available as a consultant for establishing service standards for call centers, you can email me at: contact@queuestar.com if you think I could be of assistance.
Good Luck with your improvement efforts!
Jean