How to i pass instances through a remote event?

I am making a drag tool for filtering enabled, but i can't pass rays or instances (the part that i want to move) through a remote event. I managed to decompile the rays in to the six numbers, but i still cant grab the part.

before i separated the client and server, the grabber worked fine on solo mode, so the problem is with the remote events.

Here is my local script

function onMouseDown(mouse)
	if true then --ill change this to test for grab-able blocks later
		mouse.Icon ="rbxasset://textures\\GrabRotateCursor.png"
		part = mouse.Target
		local hitPoint = mouse.Hit:toObjectSpace(part.CFrame).p
		local instances = {part}
		script.Parent.Script.StartDrag:FireServer(part, hitPoint, instances)
	end
end

This is my Script

script.StartDrag.OnServerEvent:connect(function(mousePart, hitPoint, collection)
	if true then
		local part=mousePart
		dragger = Instance.new("Dragger")
		dragger:MouseDown(mousePart, hitPoint, collection)--This is line 8 where the error is from
		pcall(function()  end)
	end
end)

My error is

11:30:14.336 - Unable to cast value to Objects

11:30:14.337 - Script 'Players.Player1.Backpack.Drag.Script', Line 8

11:30:14.337 - Stack End

My question is how do i pass instance based variables like part IDs through remote events.