How to delete a repeated object in layout

Can you be a little more specific about what exactly you want to delete. Essentially everything in a layout is an OA object which maybe deleted with dbDeleteObject(). So I think the question in your case is how to identify what exactly you what to delete. For example you might use the dbGetOverLaps() function when the objects you want to delete are in a specific bounding box or you might filter by layers or whatever...that's why I'am asking to be a little more specific

HI mbracht, thanks for quick replay 

suppose let us consider  metal1 which is repeated 20 times with same interval of distance where other devices and metals also present in between the metal1. but I want to delete only metal1 which are having same distance  

ok - assume you have a list of metal1 rectangles with one being the source and the other ones the copies.
To determine whether a shape is copy you need to check the objType, the width/height and the layer.
Assume moreover that the source rectangle is on the very left and the copies on the source's right hand side.
Select the original and the run the below code:

(defun getWidth (rect "d")
   (xCoord (upperRight rect~>bBox))-(xCoord (lowerLeft rect~>bBox)))

(defun getHeight (rect "d")
   (yCoord (upperRight rect~>bBox))-(yCoord (lowerLeft rect~>bBox)))

sourceRect = (car (geGetSelSet))
sWidth=(getWidth sourceRect)
sHeight=(getHeight sourceRect)
cv=(geGetEditCellView)

copies = (cdr (sort
   (setof shape cv~>shapes
      shape~>layerName==sourceRect~>layerName &&
         shape~>objType == "rect" &&
            (sprintf nil "%2.3f" (getWidth shape))==(sprintf nil "%2.3f" sWidth)) &&
               (sprintf nil "%2.3f" (getHeight shape))==(sprintf nil "%2.3f" sHeight)
   )
   (lambda (s1 s2) (xCoord (lowerLeft s1~>bBox)) -  (xCoord (lowerLeft s2~>bBox)))
))

(foreach copy copies
   (dbDeleteObject copy))

The code collects the source and  all copies (that's what the setof() does) and then sorts them left to
right (this is what sort() does). The cdr() eventually returns all but the first shape (the sourec shape) coming from setof()
I've made quite a few assunptions which I don't know whether they are the case for you...so this is just an example which
probably doesn't reflect exactly your scenario but it might at least give you a rough idea how to do that.