Brad Pitt may not be on the best terms with his and ex-wife Angelina Jolie’s children, but an insider has confirmed the Bullet Train actor still has visitation rights with his younger tots: Shiloh, 18, and 15-year-old twins Vivienne and Knox. “He has virtually no contact with the adult kids,” the source noted, referring to Maddox, 22, Pax, 20, and Zahara, 19. “His engagement with the younger kids is more limited in recent months because of his filming schedule,” the insider explained, as the Oscar winner, 60, has been in Europe to film F1. “[Angelina] has the kids most of the time, but per the…