According to Ilgan Sports, three members of Girls Generation decide no to renew their contracts. This 9th of October, SM Entertainment partially confirmed the news, saying that « some of them didn’t renew their contracts ». According to the report though, the three members are Tiffany, Seohyun and Sooyoung.

Tiffany want to go abroad and study acting in the United States, as for the two other girls, they would like to focus on their acting career. Until now, it seems only Taeyeon, Hyoyeon, Yuri, Yoona and Sunny renew their contracts.
Moreover, SM Entertainment stated that the other members are not thinking to disband, and future promotions will be thoughtfully decided after some discussions with them.
We will probably get more informations about it all soon.
Journalist: Naho
Source: Naver