Script causing unplayable lag, any help?

You forgot to put a wait in the RenderStepped event, and remember RenderStepped fires every frame so of course that would be a bit laggy, but all you have to do is put a wait() in it. here's the code

local plr = game.Players.LocalPlayer


local soundRegions = workspace:WaitForChild("SoundRegions")
soundRegions = soundRegions:GetChildren()

local soundManagement = {}

for _,region in pairs(soundRegions) do

    local info = {}

    local region3 = Region3.new(region.Position-(region.Size/2),region.Position+(region.Size/2))
    region.Transparency = 1

    info.Region = region3
    info.Sound = script.SoundRegions:FindFirstChild(region.name).Sound

    table.insert(soundManagement,info)

end

game:GetService("RunService").RenderStepped:Connect(function()
    wait() -- Put The Wait Here So It Doesn't Lag Out
    for _,soundInfo in pairs(soundManagement) do

        local region = soundInfo.Region
        local sound = soundInfo.Sound
        local parts = workspace:FindPartsInRegion3WithWhiteList(region,plr.Character:GetDescendants())

        if #parts > 0 then

            if not sound.IsPlaying then

                sound:Play()
            end

        else

            sound:Stop()
        end
    end
end)

I don't know much about Region3 but the best you can do is make parts around the map and with sounds that play when you touch those parts.