My parents did not determine who gets what from the family heirlooms and personal effects. There are six kids. Where can we get information on managing this tense situation so we all end up getting along ?

The family just has to decide, if you have to, it would be fought out in probate court

See if you can sit down with an uninvolved neutral third party and discus this. Maybe someone who knew your parents, or your family minister, or something. Having a third party there can help keep people and good behavior and make the situation less tense. Everyone just has to be willing to compromise about it. Worst case, like Fr_Chuck said, you can go to court over it. Good luck!

IF all parties would agree, you assign as peggy noted an independent third party to decide