If the targeted creature is an illegal target by the time Rite of Replication resolves, the entire spell is countered. You won’t get any tokens.

As the token or tokens are created, they check the printed values of the creature they’re copying -- or, if that creature is itself a token, the original characteristics of that token as stated by the effect that put it onto the battlefield -- as well as any copy effects that have been applied to it. It won’t copy counters on the creature, nor will it copy other effects that have changed the creature’s power, toughness, types, color, or so on.

The tokens see each other enter the battlefield. If they have a triggered ability that triggers when a creature enters the battlefield, they’ll all trigger for one another.