When you say "split", what do you mean? If referring to the split pin, that's just the design of the pin and doesn't mean the cable is split, or a "Y" situation. Are you using the cable for low-level signal transfer? If so, just be sure to use a good quality cable with good shielding for that length of run. If you choose a good quality cable, don't worry about the wire gauge. The purity of the copper conductor is also important. Here's a good quality cable, for example. These are great without breaking the bank.
https://www.svsound.com/products/soundpath-rca-audio-interconnect-cable?variant=11658765190