Dear Ashok Kumar
You should do Thrmal insulation of your up stair room.If there is space in east and south of your room, you should construct verandha or made temporary arrangement as like shed of sheets etc to protect the walls from direct heat from the sun. The other reamedy to insulate walls and roof. You should visit website gharexpert,com where you find lot of articles about construction and thermal insulation and energy efficent home. For ready referace link is given below.
http://www.gharexpert.com/articles/Finishing-1607/Thermal-Insulation-Home_0.aspx