Overheating

The cooling system probably has an air bubble stuck in it and it needs to be bled. Look up the bleeding procedure for your car on Bimmerfest or Bimmerforums.

I checked the cooling system but it is not that. the fan is working, there is a new water bottle added in as well. The thermostat is now removed and it only heats up in traffic.

Well, if it's overheating and there is coolant coming out of the reservoir, it's definitely the cooling system. When you replaced the bottle, did you bleed it properly? Like I said, there is probably an air bubble or some type of blockage preventing coolant flow.

yes, Silverton radiators fitted it on and they bleed the system and checked the water flow.

Had the car been overheating for more than a minute or two at some point? How does the oil look? And the coolant too for that matter?

It could be a bad head gasket causing the excess coolant pressure.

Yes it would overheat in traffic then I had to switch it off or usually when it heats up in traffic I try to get onto a open road where i drive it at 60km/h n then the heat gauge drops back to half

Yeah, this could be a head gasket issue. Your engine has an aluminum cylinder head, and being much softer than iron, it tends to warp when it is overheated for a long period of time, which in this case could be as little as 5-10 minutes. What does your oil look like? Any chocolate milk color?

I skimmed head. New bottle. New thermostat. New water pump new bleeding hose and is still over heating

When you say "skimmed head", do you mean that you replaced the head gasket and had the head resurfaced? Assuming the job was done correctly and there wasn't an error causing your overheating issues (been there, done that) do you have any other coolant leaks? Is your fan functioning?