How can I FIX INDEX NIL WHITH LEADERSTATS?

Local TycoonNumber = 1

script.Parent.Touched:Connect(function(hit) -- this is not the player
    local player = game.Players:GetPlayerFromCharacter(hit.Parent)
    if player.Parent.Owner.Value == 1 then 
        if game.Players.LocalPlayer.leaderstats.Money.Value <= 0 then
            game.ServerStorage.Buyable_Items.Droppers.Dropper1.Parent = game.Workspace.A 
        end 
    end 
end)

Since you are using the Touched function, which can only be used for server scripts, I'm assuming you're not using a local script. If so, in line 5, you are attempting to access the LocalPlayer, which you can only access from a local script. That's why it is returning nil. You can use game.Players:GetPlayerFromCharacter() on the parent of the "player" variable, then access the leaderstats from there.

local TycoonNumber = 1

script.Parent.Touched:Connect(function(player) 
    if player.Parent.Owner.Value == 1 then 
        local plr = game.Players:GetPlayerFromCharacter(player.Parent) -- gets the player from the character
        if plr.leaderstats.Money.Value <= 0 then -- NOW YOU CAN ACCESS THE LEADERSTATS
            game.ServerStorage.Buyable_Items.Droppers.Dropper1.Parent = game.Workspace.A 
        end 
    end 
end)

Hope it helps