According to Osho, samadhi arises only in relaxation; if meditation brings stress, don’t resist it—intensify it consciously to its climax. For most people, trying to relax adds more tension, so move through total, deliberate tension until effort is exhausted. At that peak, the grip releases by itself; relaxation happens spontaneously, and only then can samadhi open.
If meditation makes you tense, tense up fully and consciously until you’re spent—then relaxation (and the doorway to samadhi) appears on its own.