@Tim Edwards Ex.7e: When I do area selection and copy, Metal3 doesn't get copied. But M2 and VIA2 are copied. As a consequence, I get a DRC error asking for M3 over Via2. Can you please let me what I am doing wrong? Kindly let me know if you need more information to help resolve this.

I'm not sure what you did. The shape on the right is the original, or the copied one? Did you use the

a

key to do an area selection (of everything)?

Shape on the right (under the box) is copied. Yes. I first placed a big box over the original cell and I did use the "a" key to do an area selection.