I was looking at your System Requirements page but am still not sure if my iMac will run unity am running an iMac 27-inch, Late 2012 version 10.14.6 with a 2.9GHz quad-core Intel Core i5 processor (Turbo Boost up to 3.6GHz) with 6MB L3 cache and 8 GB 1600 MHz DDR3 of memory and an NVIDIA GeForce GTX 660M 512 MB Graphics card will this be enough to support 3d unity
I had a 2011 MacBook Pro with no supported graphics card and Unity 3D worked fine on it. I have since upgraded my laptop though.
I have Unity running on a 2011 Macbook Pro. It's not ideal, but it does run. I wouldn't use it to run high end scenes using HDRP, but it can be used.