You cannot keep 3 adult rats in a 10 gallon tank. The build-up of ammonia in such a short period of time would kill them.

Your going to need another male anyway, to keep the breeder male company while the females are resting or rearing their offspring. The females need to be separated from the male before they give birth as they go into heat right after having the babies, and can become pregnant again right away. This is not good for her or the developing or nursing babies, and can result in small litters, debilitated female rats and thin pups. SO, you'll need another female rat too, to keep the resting female company when she doesn't have a buddy. You will need 1 tub for the males, 2 tubs(one for each female while they are birthing, since baby stealing can occur and babies can get hurt and even killed), a resting female tub, and 2 tubs for separate sex weaned babies. They can get pregnant as soon as 5 weeks old, so it's best to wean them at 4 weeks and separate by sex so this does not happen.

So no, 10 gallons do not work unless you're using it for ONE female rat and her offspring(but even then, that small of a tank cannot be used for long, only until the babies are 2 weeks old or so, then they need a bigger enclosure).