It depends how big is the start and how warm is the nuc box.
Then if you feed the nuc, they have not space to lay when yiu fill cells with sugar.
But I do this way with my 3 frame mating nucs.
- first it takes 10 days that the queen emerge and it start to lay. I give tio queen only one frame of bees.
- when the queen lays, I give a frame of emerging bees. Now the queen can fill those 3 frames with brood.
- if honey flow is on, they get one frame honey and that I put into a big hive.
- the new bees start to fill the nuc about 4 weeks after laying start.
- it is time to get more room and the nuc fills 6 frames.
- Now I give again a frame of emerging brood, and the nuc will fill the whole box of Langstroth.
- if it does not succeed, I give more emerging brood.
This way 3 frame nuc will be triple size in 5-6 weeks.
If you let just nuc live its own life, it is unsure what happens. Honey flow will fill half of the nuc and it is impossible to grow.
If you have a mere nuc, start should be 5 frames.
Smaller nucs are not able to live in practical sense. They are too slow. It is better to use brains even if you are a beekeeper.
But if you make a 5 frame nuc inside yield period, it makes a big hole into main hive's yield.
One box bees from main hive may totally ruin the honey yield.
After yield season you may split the whole hive and put a laying queen into each box.
6-box hive and you get at least 4 good hives for winter, even here in north.