My mother is having frozen shoulder, took physiotheraphy treatment for 1 month but no relief. How long it takes to recover? Any other treatment?

6months to one year. Best to wait for shoulder to calm down then work on motion it is scary but the motion does return.A lot of things have beem tried showed nothing made it better faster let it run its course pt gentle at first increasing as pain improves.
Possible injection. Frozen shoulder can take up to a year to resolve. Therapy is usually the best treatment. Occasionally injection of the shoulder can calm some of the inflammation. Rarely breaking up the adhesions by a "manipulation under anesthesia" is needed. This is sometimes combined with an arthroscopy of the shoulder.
Patience. As others have said, it takes a long time. Sometimes, it can take up to 1 1/2 years to resolve. There is even a study that shows the exact same results in 1 1/2 years whether we 1. Do absolutely nothing, 2. Perform surgery, or 3. Do physical therapy. Sometimes, patience and time is all that it takes (some call it benign neglect).