Standard TTD reporting does not have a :10 metric.
To get reporting for :10 views in TTD, you should review the Expand VAST events numbers, this is the proxy for the :10 second view in their reporting. As a workaround, Sharethrough fires all associated Expand beacons at the :10 view mark so you can trust the Expand VAST event number as a :10 view.
In order to generate reporting on the metric, use the HD Reporting. You can also create your custom template builder for more advanced reporting.
1) To access the HD report select High Definition Reporting on the top right of your screen inside TTD's platform.
2) Then select your advertiser, date range and select the "Combined Pivot Report"
3) The downloaded report, is a pivot table of all your data, you will need to update your pivot table fields to include the VideoEventExpand checkbox which is a proxy for the 10s view.
4) Results (10s views) will be added in your reporting under the expand event.