there are multiple ways the best way is having it hold the soothe bell and walk with it and keep talking to it
Riolu evolve by happiness during the day.
in the safari zone
Safari zone.
No one
answer riolu doesnt evolve by level it evolves by care and love
have po kemon red in
in the meadow
Riolu? Check serebii.net, they should have it.
If you don't want to wait 70 days for a Riolu, trade the free Riolu you can get in Diamond and evolve it.
the safari after you beat lance once
In the Safari Zone(Encounter Rate is rare)
Catch Riolu in the Safari Zone after unlocking the blocks.