First of all, what species of quail?
I'm assuming coturnix since that seems to be the most common. In that case, the minimum space recommendation i 1 square foot per bird, but more is always better - and you should never keep more than one male above ~6 weeks of age in a cage that has females. So assuming you have 6 boys and 6 girls, with your cage being 12 sqft you could keep one male and all the girls in there and place extra males in a different cage, eat them or sell them. I say could - but if those quail really are coturnix, according to what I've read the smell - and amount of dust - is very likely to make you reconsider very soon - and the more birds you have, the worse.
As I see it, the main issue with the cage (apart from being inside) will be egg collection. It looks like the whole front opens? That will definitely make it possible to collect the eggs from all corners, but you might have birds all over the house by the time you finish. If they are tame, they might be easy to catch but having to catch 7 birds every day might become rather annoying. Some smaller doors at the ends might be better, but as the cage is both deep and long they could lay eggs in hard-to-reach positions. You can reduce that by making all hard-to-reach positions appear very open and giving them cover in the places where you want them to lay.
You can make the birds lay all year by giving them 14-16 hours of artificial light a day, even if they are outside.