I have had surgery for a fracture of proximal humerus greater tuberosity with rotator cuff repairs two weeks ago. When will I get back use of my arm?

6 months. Usually begin passive motion early (within a month). Active motion at 4-6 wks so you don't pull against the repair early on. Strengthening at 8-12 wks depending upon healing. Full recovery 6-12 mos.
Shoulder Fractures. Dixie, a lot depends on your specific injury, but in general both fractures and a rotator cuff repair take about 6 wks to heal initially. For that time you're in a sling not doing much to protect the repair. After 6 weeks gentle motion exercises start, and around 8-12 wks things may seem semi-normal. Probably 3-6 months to really feel like you're over it. Hang in there, it will get better.