By default, Unity places objects in the render queue specified in their Unity shaderA program that runs on the GPU. More info
See in Glossary. You define this value using the [Queue]
SubShader tag.
You can override this value on a per-material basis.
In the Unity Editor, you can do this in the material Inspector by setting the Render Queue property. In a C# script, you can do this by setting the value of Material.renderQueue using the Rendering.RenderQueue enum.