So what kind of Coturnix are we talking about that you are wanting?
The c.Coturnix or the j. Coturnix. If the j, Coturnix are you wanting the smaller Pharoah type or Jumbos. Each requires a little different space. But yes cages - larger is better.
The c. Coturnix - what everyone calls the Button Quail, need to be inside. With them, you have more colors to choose from. They are house birds and ground dwellers. So long cages or use them as bottom dwellers of a mixed cage of birds.
The Jumbo j. Coturnix are the big eaters so they should be raised outside. Unless you don't want your mother-in-law around. And you don't mind wearing breathing masks on a regular basis.
The smaller Pharoah type - there are more colors popping up and just having a few in the house shouldn't be a problem.
No more than Parakeets or Cockateels (spelling?) and such size birds. Treat them like you would anyother house bird. But remember they are ground dwellers so will need long cages not high cages. Or add them to your other bird cages for a clean up crew.