Hi Sreenivasulureddy,
As far as I am concerned, you can't edit the number of documents shown in Home Tab.
Please have a look at paragraph 3.2 of Business Intelligence Launch Pad User.
Link: http://help.sap.com/businessobject/product_guides/sbo41/en/sbo41sp7_bip_bilaunchpad_en.pdf
Best regards,
ilias