Put your chart object on a layout based on the table where you have defined the radio button field.
In that table, define a summary field as the "count of" this field (any field that is never empty of data can be used here).
In your chart object, specify the radio button field as your X series (to label the bars).
For your y-series, specify the summary field.
In your data source options, make sure that the options for "found set" and "summarized data" have been selected.
Now, if needed, perform a find for the records you want to serve as data for your chart.
Then, this step is required, sort your records by the radio button field. This is needed in order to group your records by the value of the radio button field. Without the sorting you won't see one bar for each value selected in the radio button field.