Acts as an important epigenetic regulator through multiple silencing mechanisms (PubMed:23555312, PubMed:24726328, PubMed:24719467, PubMed:25211139). Involved in transcriptional gene silencing (TGS). Plays a role for DNA methylation in the RNA-directed DNA methylation (RdDM) pathway. Contributes to the methylation status of the retrotransposon SN1. Required for DNA methylation only at a subset of RdDM target loci (PubMed:24719467). Plays a regulatory role in RdDM through retention of non-coding RNAs (ncRNAs) in normal cells. Helps to retain Pol V-transcribed RNAs in chromatin to enable their scaffold function and is required for genome-wide Pol IV-dependent siRNA (24 nt siRNA) production that may involve retention of Pol IV transcripts (PubMed:24726328). Involved in association with RRP6L2 in the silencing of the solo LTR locus. Controls levels of ncRNAs from the solo LTR locus. Seems to function independently of the RdDM pathway (PubMed:23555312). Functions redundantly with RRP6L2 in the regulation of FLC locus. Participates in the maintenance of trimethylated 'Lys-27' (H3K27me3) at FLC locus via the regulation of antisense long non-coding RNAs (lncRNAs) and the regulation of diverse antisense RNAs derived from the FLC locus (PubMed:25211139). Seems not involved in the exosomal RNA degradation (PubMed:24726328, PubMed:25211139). Can complement the growth defect of a yeast mutant lacking RRP6 exonuclease (PubMed:18285452). Also detected in the nucleolar vacuole. A number of isoforms are produced. According to EST sequences. No visible phenotype under normal growth conditions (PubMed:18285452, PubMed:25211139). The double mutants rrp6l1 and rrp6l2 have a late flowering phenotype (PubMed:25211139).