It's not possible. In PRC, you need to create separate PointSet objects for this purpose. But you can join them into one PartDefinition:
...
OdPrcPartDefinitionPtr newDefinition = OdPrcPartDefinition::createObject();
pPrc_FileStructure->addObject(newDefinition);
...
for (int k = 0; k num_point; ++k)
{
OdPrcPointSetPtr pPointSet = OdPrcPointSet::createObject();
pPointSet->styleId() = OdPrcCategory1LineStyle::createByColor(getR(k), getG(k), getB(k), *pPrc_FileStructure);
OdPrcName name;
name.setName(<point name>);
pPointSet->name() = name;
pPointSet->setBehaviourBitField(PRC_GRAPHICS_Show);
pPrc_FileStructure->addObject(pPointSet);
pPointSet->point().push_back(OdGePoint3d(X(k), Y(k), Z(k)));
newDefinition->representationItem().push_back(pPointSet->objectId());
}
newDefinition->setBehaviourBitField(PRC_GRAPHICS_Show);
pPrc_FileStructure->fileStructureTree().partDefinition().push_back(newDefinition->objectId());
...