Your cables will need to match the speed associated with the input of your TV. HDMI 2.1, at full data rates, works at up to 48Gb/s. HDMI 2.0, at full data rates, works at up to 18Gb/s. So, you just need to ensure your cables meet those specifications.
Several 4K TVs on the market, support higher than 18Gb/s data rates. This includes the Sony 900H and the LG CX series OLED TVs. This is to allow for 120Hz 4K gaming to take place. So, you would need 48Gb/s rated cabling. Your receiver and all your gear would need to support the higher bandwidth as well. This has been a problem with Yamaha and Denon receivers that claim 8K compatibility.
