RTL 360 x 360 (Gear S2) have device for 2.3.1.1 OS

What is OS?

Into SDK 2.4 r 6 i don’t see the e ability to develop for thai version.

 Here – we read:

“Note

• Tizen 2.4 Rev3 SDK supports developing applications on multi-platform environments: 2.4, 2.3.1, and 2.3 based applications.”

Does I need download 2.4 Rev3 SDK for build project for GearS2 2.3.1.1?

If yes -where can i download this sdk?

Thank you