In terms of memory, consoles have limited amounts of memory (or RAM) - this is not to be confused with storage (below) - if you're seeing an error relating to out of memory or low memory, this may be due to the use of mods that consume a large amount of RAM. This is more common on the lower-end versions of the consoles (Xbox One S / Xbox Series S or non-pro version of PS4)
For storage, consoles are allocated limited space (usually a max of 1GB) for mods across all games, independent of how much free storage you have. You may need to check what you have installed on your console and remove some things to find the space. Also, some of the mods are close to 1GB in size, so you may only be able to have one of these larger mods installed at a time due to the space limitation.
Clearing your cache, or reinstalling the game, can sometimes fix issues around this, as sometimes the storage is still considered used, even after removing or deleting some mods.