Question
My Tree has turned brown on one side can you give me an solution

Answer
Elizabeth:

I am assuming that you are referring to the Redtip Photinia, a shrub that can can get tall and tree-like.  If entire branches with leaves are turning brown on one side of the plant, this may indicate some sort of progressive stem decay disease. Did the browning happen suddenly or was it something that got worse over time?  If it happened suddenly, then a main stem of the plant may have been damaged.  Try taking a look at the bases of the larger branches and even the bases of the main trunk for evidences of stem injury where the bark may have been injured/removed.  It may be merely a physical injury rather than an bona fide infectious disease.  Selectively removing the dead portions is advised if it doesn't affect the plant severely, then replacement may be the best option.

Regards
Steve