Essential component of the RMI complex, a complex that plays an important role in the processing of homologous recombination intermediates to limit DNA crossover formation in cells (By similarity). Component of the BTR double Holliday Junction dissolution complex, which is involved in homologous recombination during meiotic double strand break repair in the germline (Probable). Promotes top-3 binding to double Holliday junctions (DHJ) and hence stimulates top-3-mediated dissolution (By similarity). Stabilizes and positively regulates the localization of the BTR double Holliday Junction dissolution complex components rmif-2 and him-6 at nuclear foci during meiotic recombination (PubMed:27011106, PubMed:34252074). Plays a role in double strand break repair by regulating the accumulation of rad-51 at double strand breaks during meiosis (PubMed:27011106). Positively regulates chiasma formation and DNA crossover designation, formation and positioning on chromosome arms (away from the chromosome center) during meiotic homologous recombination (PubMed:27011106, PubMed:34252074). Specifically localizes him-6 to DNA crossover sites along chromosome arms (PubMed:27011106). Also plays a role in the repair of non-crossover homologous recombination intermediates during meiosis (PubMed:27011106). Not required for chromosome pairing and synapsis (PubMed:27011106). Together with rmh-2, positively regulates larval development (PubMed:27011106). Component of the RMI complex, containing at least top-3, rmh-1 and rmh-2 (By similarity). Component of the BTR double Holliday Junction dissolution complex composed of at least him-6, top-3, rmh-1 and rmif-2, which is involved in double strand break repair in the germline (Probable). Interacts with rmif-2; the interaction is direct and is required for mutual stability and localization at nuclear foci (PubMed:34252074). May interact with him-6; the interaction is required for mutual stability and localization at nuclear foci (PubMed:27011106). May interact with top-3 (PubMed:27011106). In early development, first localizes to the nucleoplasm then as development proceeds progressively accumulates on foci on chromosomes (PubMed:27011106). Co-localizes with rmif-2 in nuclei foci during pachytene in meiotic prophase I (PubMed:34252074). Localization at nuclear foci is dependent on rmif-2 during meiotic recombination (PubMed:34252074). Accumulates at nuclei foci as pachytene progresses, peaking at mid-pachytene (PubMed:27011106). Co-localizes with him-6 at mid-pachytene and late-pachytene in meiotic prophase I (PubMed:27011106). Does not localize to nuclei foci during diplotene (PubMed:27011106). Localizes to nuclei foci at crossover sites and non-crossover sites on DNA homologous recombination intermediates (PubMed:27011106). Co-localizes with cosa-1 and msh-5 at DNA crossover sites during meiotic homologous recombination (PubMed:27011106). Expressed in the germline (at protein level). Expressed in the germline throughout early pachynema in meiotic prophase I (at protein level) (PubMed:27011106, PubMed:34252074). Expression progressively increases during pachytene in meiotic prophase I, peaking during mid-pachytene and reducing at late pachytene (at protein level) (PubMed:27011106). Belongs to the RMI1 family.