Assuming i guessed correctly are you trying to define the gutter widthor gutter position.
Indesign margins and gutter.
Planning your indesign pages using margins and columns bookmachine this is an excerpt from nigel french s book indesign type.
Choose layout margins and columns.
You can set the gutter size from the new document menu when creating a new indesign project.
Enter values for top bottom left and right margins as well as the number of columns and the gutter the space between columns.
Gutter widths should relate to the body text leading value.
Open the pages panel window pages and select the thumbnails for the pages you wish to change.
Use margins and column guides to position content.
Indesign uses the first definition in margins and columns so i m going to guess that is what your question is about.
To achieve uniform spacing set your gutters to the same value as or a multiple of 1 5 or 2 for example the leading of the text.
To adjust column guides manually drag them horizontally to new positions producing unequal widths.