Take advice on maintaining the 30 minute FR of first floor if you penetrate it.
The regulations require you to prevent the spread of cold fumes and gases as well as fire.
Putting holes in your 1/2 inch ceiling is a good way to breach both intended safeguards.
Doing so above a kitchen cooker [chip pan fires, fat fires etc.] constitutes a significant fire and smoke risk.
Most people simply duct horizontally to external air.
Given your other recent post, you seem to be giving the kitchen the works - the best of luck with it, its the heart [or stomach
] of a good home.
If you're considering the ubiquitous recessed downlighters, these should be fitted with fire hoods, again to maintain the integrity of the 1st floor.
Consider surface mounted spots with integral transformer as an alternative.
ONQ.