1-what about proxy ( like vray proxy) ? to use very high polygon (like trees)
Well, proxies as in vray proxies are optimized instanced meshes for that particular render engine, on the other hand instances (which is quite the same but off the box) will be supported in the v1.x series of octane (Radiance, please correct me if I'm mistaken) and then you can stick as many trees as you please where ever you want
2-what about netwark render? to make huge scene and render it esay ?
The problem with "huge" scenes is the amount of vram your gpu's got, that's the actual limit, it also cap's the top resolution, it's said before, as this technology evolves will see more ram in our gpu's for now they can handdle pretty big scenes, if you want more speficic anwser search the forum for vram or take a walk thru the gallery and wip to see what can be done.
3-what about night light its support to 3dsmax lighing?
In the oncoming release octane will have emitters, that is, any mesh will be able to act as a light source using a material, with that you can do any light you can think off and probably many more you haven't figure out yet. It's the usual way for unbiased engines being as they are more phisically acurate. If you mean moonlight, you can use an enviroment HDRI map of a night scene for a more realistic result.
4-what about 3dsmax plugin ( vray scutter , itoo , tree storm ,and others ) ?
Anything you can do in 3dmax and export to obj is suported by octane, octane doesn't work inside max, your geometry needs to be exported and then imported in octane there you can fine tune your previuosly assigned materials setup lights and move your camera around for that perfect shot. In those particular cases you mention all work just fine, but vray proxies (or other 3rd parties proxies for that matter) can not be directly exported to obj as they need to be converted to standard meshes prior to export.
5-what about 3dsmax scripts its support it ?
As stated above, do your modeling job in max using anytool, plugin or script, assing your materials and setup your uvmaps, if you feel like it you can add a directional light to use as your sun or setup a camera to use as a starting point (well the camera and the sun can only be exported using octane's max script), althou if so easy to move your camera around in octane that you might skip that step. Then with all this, export to max using either the octane script or the inbuilt obj exporter and this is where the magic and fun begins.
When in doubt, download the demo and the demo suit with the examples, see the videos, check the obj export forum thread and use your own models, and if your not convinced... well...
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You are probably doing something wrong