By default My Site deletion notification email sent to manager. But is there any chance to send same email to administration account in sharepoint 2010 .

Unfortunately you cannot customize the out of the box MySite Cleanup Job.  If you want to make any changes to the cleanup job behavior, you'll have to stop the out of the box cleanup job and develop your own job.

Hi,

 I know how to create timer job,But I don't know how to develop custom mysite cleanup timer job.

do you have any idea.If you have any article please share me that one.

Creating this would depend on the business logic required.  A timer job like this could be fairly complex, depending in your requirements.