Hi, welcome to the forum! Pollutionblues is correct above. Don't fall for the marketing - IPv6 doesn't impact your gameplay in any way, it's one big placebo effect. Since the vast majority of home networks run on IPv4 you should use IPv4.
If you want to prove for yourself that it doesn't affect your connection, just think about what it actually is. ISP's ran our of numbers to use for their IPv4 format, so they came up with IPv6 which changed the number format and allowed for more IP addresses to be created. That's it folks!