How to Rotate Object around point only 90 Degree.

currently I try a small game with VR HTC Vive . I make a long object and set parent it to VR controller when i catch it . but i want to set Rotation of a long object to corner of my VR controller (90 degree of VR controller), so how can i do ? 81427-bandicam-2016-11-02-14-06-01-443.jpg

Have you tried setting the local rotation of the object, i.e.

transform.localRotation.eulerAngles.z = 90;