OpenGL 2.1 Texture3D Clip Plane

I am working on volume rendering to visualize DICOM images. We use OpenGL 2.1 and it is implemented through GL_TEXTURE_3D functionality.

We need to render the Cut view of the DICOM slices, and tried using gl_ClipDistance and GL_CLIP_PLANE0 but both are not working. So what is the proper way to render a cut view when using a 3D texture functionality in opengl. Refer imageCutView