This can't be done with a script, but there's another command in the Actions list that can do it. You'll find it under Document Processing - Set Open Options.
But I am unable to find this optin under Document processing.
I am using Acrobat 9 Pro version.
Please help me on this.
It's possible it's not available in your version. You should consider
upgrading to Acrobat Pro XI.
In Acrobat 9 Pro use an batch sequence.
For future projects, depending upon how you create your PDFs you might be able to set the Initial View for the PDF to show the page and bookmarks. It is also possible to set this using the PDF's properties. There are also 3rd party tools that can set the Initial View.