Modpack version

I have a question, i was playng a Minecraft modpack with my Athernos, i found that the Modpack was updated to a new version (1.12.2) But in the modpack you can find mods that doesn't exist on 1.12.2 like Traincraft.

Now my Question:

Can the server stay on the Modpack version 4.0.2? (This version) Without Updates please?

Thanks

Colony [Kinetic]

There is no way to have a older version? If i upload it on Technic maybe?