My friend is coming back to India from Dubai and is bringing a PS4 for me, as it is cheaper there. It is new and in the original, unopened packaging. He has his own carry-on baggage and adding the PS4 would exceed the weight limit. Would it be safe from either damage or theft to pack it in his checked luggage?
It is fairly safe (external damage/theft) to bring gaming consoles in checked-in baggage. Just pack it well and if possible, ask the person at airport check-in desk to put a fragile sticker while checking-in the luggage.
Disclaimer: I should not be held responsible if you end up with a bricked console but people do it all the time.
Never put anything of value in check-in luggage.
No airline and no insurer will pay for damages and loss, and there are many options for things to disappear from your luggage.
It is also not a good plan to transport anything in check-in luggage if is likely to get damaged when thrown, as all luggage, even with Fragile stickers, is often handled in such a way that it is likely to break.