When comparing the two of cable, 3C2V has smaller diameter than RG6. RG6 cable can sometime be seen as Quad shield cable. Both these cable can be used in TV signal receiving but RG6 is the most suitable when receiving digital signal such as Satellite Television and DVB-T.
3c2v is 75 ohm and used for tv and radio.
rg58 is 50 ohm and used for ham radio. (not radio!)