  Diffuse radio sources associated with the intra-cluster medium are direct
probes of the cosmic ray electrons and magnetic fields. We report the discovery
of a diffuse radio source in the galaxy cluster RXCJ0232.2-4420 (SPT-CL
J0232-4421, $z=0.2836$) using 606 MHz observations with the Giant Metrewave
Radio Telescope. The diffuse radio source surrounds the Brightest Cluster
Galaxy in the cluster like typical radio mini-halos. However the total extent
of it is $550\times800$ kpc$^{2}$, which is larger than mini-halos and similar
to that of radio halos. The BCG itself is also a radio source with a marginally
resolved core at $7''$ (30 kpc) resolution. We measure the 606 MHz flux density
of the RH to be $52\pm5$ mJy. Assuming a spectral index of 1.3, the 1.4 GHz
radio power is $4.5 \times 10^{24}$ W Hz$^{-1}$. The dynamical state of the
cluster has been inferred to be "relaxed" and also as "complex" depending on
the classification methods based on the morphology of the X-ray surface
brightness. This system thus seems to be in the transition phase from a
mini-halo to a radio halo.
