可唔可以帶condom上機？

Why not? If a 寄艙行李checked baggage. It will be sure ok.
手提行李一定要放在合理地方. 如手袋.
重要不可使他人不安. 更不可在坐位上使用

as long as it is packed in the factory-sealed packaging condoms can be brought to the flight, either in hand-carry or checked luggage

however, custom officials has the right to order you to open the package (and make your condom useless) shall they suspect it is something other than condom inside