It comes out in September!
"Nobuo Sumino, the head of Shueisha's comics and contents sales department, reported in the May/June issue of The Tsukuru magazine on Saturday that the previously revealed second anime season of Kuroko's Basketball will premiere in September. The first season based on Tadatoshi Fujimaki's manga ran from April to September of last year.
Sumino added that the original manga's volume had initial print runs of 300,000 copies before the anime premiered, but they rose to 500,000 after the anime. Between the April rebroadcast and the new season, he muses that the next volume of the original manga could have a print run of more than 1 million copies in August."