Any changes you made are deleted along with the record type. Once deleted, you cannot retrieve the record type unless you undo your checkout to revert to the previous version of the schema.
Select the record type you want to delete from the Name list. If you want to delete a stateless record type, check the Stateless check box and then select the appropriate record type from the list. Click OK. Rational® ClearQuest® deletes the record type from your schema.