Good afternoon, Ron! Thank you for your inquiry. This device is an unlocked GSM-compatible version of the J3. From what we're able to see, Republic mobile is an MVNO operating on Sprint and T-Mobile's networks which means that this device should be compatible with their service. However, we strongly recommend reaching out to your carrier to ensure this compatibility before making any final decisions. We hope that this information is helpful and thank you for your interest in this product!