So I am a moderator for "Maneater" and the default timing method is In game time but if you look at the leaderboard you will see that real time is still the "main column. How can I change that in game time is on the left?

Default timing method of IGT means that all runs are sorted only by the IGT, and that is the time shown on the runs. The layout of the leaderboard stays the same, with real time on the left.

If real time is not important in your game, you can switch off the "In-game timer" setting and you will have just one column for time, and you can fill it with the in-game time instead.

If you really really want both times to show but real time column being on the right side, I guess you can still keep just one column for time, and add a new variable for "real time" and it will show in the right side. I don't see a reason to do that, but almost all my games go by RTA anyway.