Mobile Tip:

If you're below lvl 62,you can agro it first to make it follow you (Go outside the redwood), Get 10x soothing balm from cave, all you need is sneak, go behind the giganotopithecus, feed the soothing balm, Then keep feeding mejoberry until it's tamed!, You could also use Scorpio, Araneo, etc (Must be tamed from cave), so the Gigantopithecus will not agro you!

More Gigantopithecus Taming & KO Tips