RNA-binding protein that binds to the consensus sequence 5'-CUCUGUAUCUUGU-3' in mRNA 3'-UTRs and modulates mRNA expression and stability. Functions redundantly with puf-5 and puf-7 in oocyte formation and organization, early embryonic cell divisions, and repression of expression of glp-1 and other maternal mRNAs in late oogenesis. Simultaneous knockdown of puf-6 and puf-7 results in ectopic primordial germ cells (PGCs) outside the somatic gonads, premature PGC proliferation in L1 larvae and germ cell death. Does not affect germline development in adult hermaphrodites. Disruption with puf-5 and puf-7 results in abnormally small oocytes, disorganization of oocyte nuclei and cells, inefficient yolk uptake by oocytes, embryonic arrest with impaired eggshell formation and cytokinesis defects, impaired repression of glp-1 in late oogenesis, and mislocalization of rme-2 to the cytoplasm instead of the plasma membrane. Puf-6 and puf-7 are >98% identical on both nucleotide and protein sequence level. Experimental approaches often do not distinguish between the two genes, which are collectively referred to as puf6/7 and are considered to be functionally redundant.