As Hipster said, what type of mods? Is it a texture pack, interface mod, items, markings, maps?
I'll list them all, though.
Texture Pack or Interface Mods go in your FeralHeart>Media>Textures folder.
Items go in your Feralheart>Media>Items folder, the Items.cfg goes in your Feralheart folder.
Markings go in your Feralheart>Media>Textures folder, the Markings.cfg goes in your Feralheart folder.
Maps go in Feralheart>Exports folder.
Hope this helped!