Did you intend to breed your rats on purpose? In general, planned breeding should only be for professional, well informed rat breeders who know what they are doing and think before they breed. It's not a profit gaining business but they do it to improve the health and temperment of rats and know a ton about the genetic line their breeders have come from... They also usually know there is a demand for their rats so they don't end up with many rats they can't find homes for.
What will you do if you can't find homes for these babies?
Good luck in finding them homes though, it's hard and there are tons of rats in shelters needing homes as well...
Seperate the sexes at 4 weeks or before 5 weeks at least. Don't want the males to get the mom or the other girls pregnate. I believe they can be adopted out at 5 weeks.