According to Osho, the 112 techniques of Vigyan Bhairava Tantra are variations of one thing—witnessing. Zen also centers on witnessing, but there’s no provable historical link; Buddha realized witnessing only after abandoning methods, not by following Shiva’s text. Thus, VB Tantra isn’t the root of Zen, though both converge on the same essential method.
They teach the same clear watching of experience, but Zen didn’t directly come from that old book.