Rokushu is the kata of grip releasing. Its name means 'six hands': the five animals, plus the snake that grips you. It is understood as a later development — a play on Sanchin — and is known in Goju-ryu and Uechi-ryu lines as Tensho.
Rokushu enters the adult syllabus at 2nd Kyu, where the complete kata is required, and remains a standing requirement through the Dan grades. A full run takes about two minutes. Its applications live inside the kakie curriculum: crane spreads its wings, crane circles its wings, snake vs tiger, snake vs standing dragon, and at Nidan the contra grips for laying dragon, leopard and crane — Rokushu applications by name.
Treat every movement as a grip being received, neutralised and released. If Sanchin teaches the body its structure, Rokushu teaches the hands their freedom — the two kata are a pair, and the pushing-hands progression runs straight through them: Sanchin boxing, then Rokushu grip releasing.