In the OSBot client, go to Advanced Settings and turn on Positions. 
  
For getting an area use this: 
  
Go to lowest Y and X co-ordinate (write it down). 
Go to highest Y and X co-ordinate (write it down). 
  
Then put it like this in the code: 
  
private Area (NAME) = new Area(highestX, highestY, lowestX, lowestY); 
  
That will give the rectangular area.