You'd need either 6 records in your table (one for each department) or 6 groups of records.
The two parts of your stacked column represent two different data series for the y-axis. Unfortunately, this requires two different fields to report the total students in each category.
Let's assume that you are basing this on your table of students. and will sort the records by department to get the 6 groups of records for your 6 bars on the chart.
You can then define two calculation fields, cInactiveFlag and cActiveFlag as:
If ( Active = "yes" ; 1 )
If ( Active = "no" ; 1 )
Then define two summary fields as the total fo cInactiveFlag and cActiveFlag.
Your two Y-axis series would then refer to these two summary fields to get the two parts of the stacked Bar.
Make sure that your data source series refers to the "found set", "grouped when sorted" options and then sort your recors by department to get your chart.