Question about Noctua Nh-U9s

Basically, any fan is suitable for overclocking. There is certainly a better choice, but it often depends on the case and whether you can install a larger one. So get to the OC screw and see what the i5 can do :-)

Look at the Noctua web site for the processor compatibility - https://noctua.at/en...
It is suitable for Low overclocking. There are better fans - but they are 35 to 40mm larger - so check your case.