Pot size help/problem??

I've transfered the plants to bigger pots about 10 days ago, i've noticed that the roots are now coming through the bottom holes. Is this ok, or do I need to put them in even bigger pots. I'm not sure on the ltr quantity, but on the bottom it says 6" and 33mm???
I'm worried they will become root bound.

Thanks

push down on the top of the soil and if it pushes back than they are completely rootbound and need to be transplanted. Transplant as few times as possible it stresses out the plant. If you are going to transplant go double.

thanks pal.