Results of Instagram channel level analytics can be found under Insights > Instagram Accounts. Here's a blog post that provides more information.
As with other channel listening sources, Instagram results will appear in Content. We collect Instagram data in batches, refreshed a few times per day. Likes and comments count (snapshot in time, at time of data fetch) for each post is shown. Therefore, the counts shown in the Content are NOT likely to match the counts on Instagram at a later time. Aggregate stats can be viewed by clicking on "Analyze Content".
Here's a sample stats view in Analyzer.