Can sacroiliitis or bursitis cause hip to lock?

Not usually: Sacroilitis is usually posterioly in your buttocks. If you feel locking or catching in your groin it could be a labral tear of your hip. I hope thus helps.

Not usually: Depends on what you mean by locking. In can be from an internal hip problem (like a labral tear or osteoarthritis) or from an external hip problem like "snapping hip syndrome" or something completely different depending on what you mean by "hip locking" . Sacroilitis usually causes very focal pain over the sacroiliac joint and can sometimes cause radiation into the buttocks, groin, hip, or leg.