@Satya K

You need to goto Dev Studio>Configure>System>Refactor>Classes. On the landing page, select 'Delete a class' and provide the class for the data type and continue moving forward with the wizard. After the wizard completes, all associated classes and instances of the data type will be deleted from the system.

@Satya K To delete a data type in Pega, ensure it is not being used in any rules like data pages, activities, or reports. First, try deleting it from App Studio under Data Types. If that doesn't work, go to Dev Studio > Records > Data Model > Data Type, locate the data type, and delete it after ensuring no references exist. If the data type is linked to a dedicated database table, go to Configure > Data Model > Database Class Mappings, find the table, and delete it if it's not needed. Clear the cache using Actions > Clear Cache and revalidate the application under Application > Validate. If the data type still exists, check with the database administrator to drop the table directly from the database. Always verify there are no broken references before proceeding