To report worst slack for a particular timing groups

Write a script to report the clock group worst slack

set_global timing_report_group_based_mode true
                foreach_in_collection path [sort_collection [report_timing -max_slack 100-collection]            path_group] {
                               set size [sizeof_collection $path]
                               set path_group [get_property -quiet $path path_group_name]
                               set wns [get_property -quiet $path slack]
                               set view [get_property -quiet $path view_name]
                               puts "Clock group: $path_group View: $view WNS: $wns"
}