Can a woman have one baby in uterus and one in tube? what do they do?

Yes: It is very rare but can happen. Usually keep pregnancy in the uterus and operate and remove the ectopic pregnancy.

Heterotopics: Yes. These are twin pregnancies with one implanted in the uterus and one in the tube. Most likely the one in the tube needs to be removed.

Rare/surgery: Since the tube is not designed to support pregnancy, it would eventually rupture as the mass expanded producing a life threatening loss of blood. When identified tubal pregnancies are removed surgically, tube and all, to avoid catastrophic loss when that would happen. Hopefully the procedure would not interfere with the uterine pregnancy.

Extremely rare: It is extremely rare but possible. . It is called heterotrophic pregnancy.