Unless you think that rapists have a "right" to custody of the children they have fathered through rape, I fail to see how that is a violation of the Constitution. (I obviously do not believe such a "right" inherently exists for rapists)
This bill would require the Regions to not take certain actions. Thus, under Article I, Section 6, Clause 7, the burden of proof is on you to justify how this bill preserves either the rights of the Regions or the rights of the People, as enumerated under the Constitution.