detailed render statistics

Please read the docs on optimizing graphics performance.

Unity has a profiler.

There are many optimization steps that can be taken. As stated in the docs, the number of draw calls is related to the number of objects in the scene, the number of lights, the kind of lights, the light settings, the shaders in use and the materials in use (and when referring to batching, also the complexity of the objects). Objects that are 300 triangles or less and using the exact same materials should have their draw calls batched in some situations (search batching) (still trying to find the doc that explains this atm...). Use fewer, simpler shaders, share materials, combine textures, combine objects, bake lighting, project shadows, use fewer, cheaper lights.

You could try some occlusion culling (either a 3rd Party or script solution or Unity 3) and/or distance culling. Unity 3 includes deferred rendering which may also provide some performance improvement. Another consideration is your LOD's both for your shaders and for your models, AI, etc. It might be more performant in select cases to swap geo, anims, scripts, etc. for more simplified versions when the camera is a certain distance away or just swap them out entirely. Distance fog would be one way to mask distance culling and/or explicit LOD mesh swaps. You can set zones with triggers to act as spawn/despawn points or visibility points to control the amount of geo in the scene or the amount of geo rendering at a time by enabling/disabling renderers as appropriate.

This Unite presentation and this Unite presentation might also be meaningful to you.