Getintent lets you use Report Biulder, which provides flexible adjustment to get the necessary reports with filtering and grouping.

 

To build an available inventory report, go to the "Reports Builder" tab in the interface and select the "available inventory" dataset:

 

 

 

You will see the information of all the traffic that is available in self-service DSP Getintent.
Let's see an example of an available inventory report: 
The amount of traffic available in Russia for the "Auto" context pages grouped by domains for 1 week
We can see two columns: domain name and the number of available impressions for it. It's better to include not much than 40% of the numbers in the report while preparing a media plan.  
Some examples of the reports: 
1. Available inventory report for Moscow grouped by device type for 1 day
2. Available inventory report for the city of Ryazan and Ryazan region on mobile devices grouped by the app thematic for 1 day

3. Available inventory report for St.Petersburg for 300x250 banner size grouped by domains for 1 day