Can someone please explain the significance of the orientation option, while placing macros? What are all the possible options apart from N/S (which means north/south I guess?), and what does it change exactly in terms of placement? A pointer to any kind of documentation on this will also be highly appreciated. Thanks!

Its just how the macro is oriented. In sky130 any valid values are allowed. In advanced technodes only N and MX is allowed. Orientation is just how the macro is "rotated" or mirrored

I see. So S (south) would mean the macro is rotated by 180 degrees? What are the other valid values in sky 130? I saw an FN in one of the design. How many degrees would that rotate the macro by?

F means flipped. MX means mirrored by X axis, MY means mirrored by Y axis. I think sky130 uses Def/lef terminalogy, which is defined in the def lef specification. Another type of terminalogy would be the OASIS one, which is different

Got it. Thank you.