This is unclear. Are you and your brother in the same room, or are you trying to connect over the Internet? Because Download Play does not require any kind of Internet connection.
If you are trying to connect over the Internet, then that would not be feasible without using Pretendo, since Nintendo shut down the Mario Kart 7 servers.
Also, if you fixed the problems in your other two threads, why not provide some details about how you fixed the problems, for the benefit of future readers?
After 5 years, I decide to use my nintendo 3ds xl again, but I am surprised that it does not connect to the internet, the console is in excellent condition. Since 2 weeks ago I've tried to connect my console to the internet, but I can connect it, the version of my console is 11.6.0-39U.
Is a normal console, I didn't install any kind of hack or smth like that and I don't have the CFW thing. What can I do? I need help.
You can update from a cartridge. Look for any of the last edited physical games.
where can I find one of those?