distance from other civilizations mod

[bladex]

you can change this in your globalparameters located in Base\Assets\Gameplay\Data

look for these lines
<Row Name="START_DISTANCE_MAJOR_CIVILIZATION" Value="X" />
<Row Name="START_DISTANCE_MINOR_CIVILIZATION" Value="X" />

major are Ai minor are CS.

where X is change the number i have mine set to

<Row Name="START_DISTANCE_MINOR_CIVILIZATION" Value="6" />
<Row Name="START_DISTANCE_MAJOR_CIVILIZATION" Value="15" />

don't set them too high though otherwise on smaller maps the AI won't even spawn if there are too many on the map.

 

[Mynex]

There are a couple mods (some are in modpacks iirc), including my own.

You also need to keep in mind that there are starting locations preferences for most civs and, as I found out myself the hard way, if the distance you've specified is going to push a civ out to see, they'll settle on the coast within your specified range.