Go to Fees collection > Search Due Fees to look for overdue fees. You can select a single, multiple, or all fees group in Fees Group by checking the checkboxes next to the Balance Master, Admission Fees, Class Fees, Tuition Fees, and so on as available in your fees group, and then selecting the class, section, and clicking on the "Search" button.

Here, you can see the list of students whose fees are due.