I found the parameter for this one. Now, "Include Items from My Items" is default checked. But, we want both of them to be unchecked in the creation page of the timesheet. Is there a parameter to unchecked the My Items chose.
If you look at <ppm_folder\server\<servername>\deploy\itg.war\js\tm for TimeSheetCreate file. This is a jsp file and contains the default value information. You are looking for the following parameter and can set them to false to achieve what you need.