cannot find Device Management on my settings list on my iPhone 6s ios 10.3.1
My personal iPhone is unlocked and not monitored by my company. I just need to access the profile & device management option in my settings
No, the update did not do that. I still have my profiles section showing on my 10.3.1 devices.
Have you tried simply resetting the device and see if it shows up? If it does not, then I would say you need to re-install your profile(s) as if installed properly, the option should be showing up.