To make a placement against a job in your WaveTrackR account, first go to the Job Manager tab and locate the job. Once you've found it, click on the icon under the Reviewing column.
Once you click on the icon, a pop-up will appear asking if you have made a placement for this job. It will display the candidates you've shortlisted for the job and give you the option to select additional candidates, in case you hired externally.
When you've made your selection, click Save, and the placement will be recorded against the job.