The info on the top right of the viewport should already show it. Depending on what version you're using, there's a button on the top right(I think it's an I) to toggle it.
I'm not sure if there's a way. You can go into the rollup bar while having the object selected, and click the browse icon. Some info of the object should show up in the browser, including tris count.
Draw helpers with information for each object (same number negative hides the text)
1: Name of the used cgf, polycount, used LOD
2: Color coded polygon count
3: Show color coded LODs count, flashing color indicates no Lod
4: Display object texture memory usage
5: Display color coded number of render materials
6: Display ambient color
7: Display tri count, number of render materials, texture memory
8: RenderWorld statistics (with view cones)
9: RenderWorld statistics (with view cones without lights)
10: Render geometry with simple lines and triangles
11: Render occlusion geometry additionally
12: Render occlusion geometry without render geometry
13: Display occlusion amount (used during AO computations).
15: Display helpers
16: Display debug gun
17: Streaming info (buffer sizes)
18: Streaming info (required streaming speed)
19: Physics proxy triangle count
20: Display object instant texture memory usage
21: Display animated object distance to camera
22: Display object's current LOD vertex count
Replies
I meant if u have a object selected can u somehow toggle only it's tri/polycount and nothing else in the scene.
http://docs.cryengine.com/display/SDKDOC2/Debug+Views
http://docs.cryengine.com/display/SDKDOC2/Debugging+and+Profiling+Tools