DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Specific core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. May direct with other members of the subcomplex RNA Pol III binding to the TFIIIB-DNA complex via the interactions between TFIIIB and POLR3F. May be involved either in the recruitment and stabilization of the subcomplex within RNA polymerase III, or in stimulating catalytic functions of other subunits during initiation. Plays a key role in sensing and limiting infection by intracellular bacteria and DNA viruses. Acts as nuclear and cytosolic DNA sensor involved in innate immune response. Can sense non-self dsDNA that serves as template for transcription into dsRNA. The non-self RNA polymerase III transcripts induce type I interferon and NF-Kappa-B through the RIG-I pathway. Preferentially binds single-stranded DNA (ssDNA) in a sequence-independent manner. Component of the RNA polymerase III (Pol III) complex consisting of 17 subunits (By similarity). RPC3/POLR3C, RPC6/POLR3F and RPC7/POLR3G form a Pol III subcomplex (By similarity). Directly interacts with POLR3G and POLR3GL. Directly interacts with POLR3F/RPC39. Interacts with GTF3C4. Belongs to the eukaryotic RPC3/POLR3C RNA polymerase subunit family.