About OptiX

it’s already installed with Graphics card drivers or needs install it, also how I know what version I have.

The OptiX core implementation ships with the display driver since version 6.0.0.

If you’re under Windows 10 you can search the driver repository for nvoptix.dll and check its version info in a file explorer. I think the library is called libnvoptix.so under Linux.

To be able to develop applications with any OptiX version you need a matching OptiX SDK available on https://developer.nvidia.com/rtx/raytracing
That SDK contains the rtGetVersion() function to check which OptiX version you’re working with at runtime before an OptiX context has been created.
Here is an example how to use that:

Applications using OptiX 6 or earlier need to ship an optix..dll with their application which contains the function table loader, resp. the full core implementation in the older OptiX 1 - 5 versions.
The dependency to the driver there is to the required CUDA driver version used by OptiX internally.
The OptiX SDK release notes always contain information on the minimum required display driver versions.

In OptiX 7 which was pre-released on developer.nvidia.com yesterday (2019-07-30, see sticky post at the top of this sub-forum), this works differently, like the rest of its API.
OptiX 7 only requires to use some headers and helper functions. No DLL needs to be shipped with the application. If you’re using the CUDA Driver API, not even a CUDA Runtime DLL.
There the version dependency between the OptiX SDK 7 and the driver is the Application Binary Interface (ABI) version of the function table defined in OPTIX_ABI_VERSION.

The display driver must contain the OptiX core implementation and if it’s found, needs to have a compatible function table or optixQueryFunctionTable() will fail with an error. This is the first thing you do in OptiX 7 and effectively the version check.
Again which OptiX SDK version requires which display driver is listed in the OptiX release notes.
At this time there are only the pre-release drivers on that OptiX SDK 7.0.0 download page supporting it.