Hi, is there an update for Create 6.0 for version 1.21.1 NeoForge, or do you plan to update this mod to a higher version in the future?

I don't know the plans of the author but the Create 6.0 update issue is about Valkyren Skies not being compatable with Create 6.0 as you can see here:
ValkyrienSkies/Valkyrien-Skies-2#1111

As Trackwork depends on Clockwork which depends on Valkyren Skies, firstly the Valkyren Skies team has to fix the issue

Yes, as okuna mentioned I have to wait for VS2 compatibility with create 6.0 before I can even think about porting trackwork.

However, I should probably keep this issue open to track in the future.