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We report the 888 MHz radio detection in the Rapid ASKAP Continuum Survey(RACS) of VIK J2318$-$3113, a $z$=6.44 quasar. Its radio luminosity (1.2$\times 10^{26}$ W Hz$^{-1}$ at 5 GHz) compared to the optical luminosity (1.8$\times 10^{24}$ W Hz$^{-1}$ at 4400 A) makes it the most distant radio-loudquasar observed so far, with a radio loudness R$\sim$70(R$=L_\mathrm{{5GHz}}/L_\mathrm{{4400A}}$). Moreover, the high bolometricluminosity of the source (L$_\mathrm{{bol}}$=7.4 $\times 10^{46}$ erg s$^{-1}$)suggests the presence of a supermassive black hole with a high mass ($\gtrsim$6$\times$10$^8$ M$_\odot$) at a time when the Universe was younger than abillion years. Combining the new radio data from RACS with previous ASKAPobservations at the same frequency, we found that the flux density of thesource may have varied by a factor of $\sim$2, which could suggest the presenceof a relativistic jet oriented towards the line of sight, that is, a blazarnature. However, currently available radio data do not allow us to firmlycharacterise the orientation of the source. Further radio and X-rayobservations are needed.

Radio Detection of VIK J2318$-$3113, the Most Distant Radio-Loud Quasar ($z$=6.44)