i want to freeze the grand total row.
it means .. last row grand total irrespective of rows the grand total column should show . if scroll is there also i want to show grand total column fit to table only.
With the default-tables it's not possible. The totals are part of the scrollable area (completly by pivots and partly by straight-tables) and therefore are moving within them. Usually is the from jyothish8807 mentioned option to set the totals on top the most suitable approach to display the totals.
An alternatively could be to use in general several objects if you want to provide an aggregated and a detailed view at the same time - maybe within a container in grid-mode.
My above mentioned approach of using multiple objects within a container should in general also work by a dynamic chart whereby I rather doubt that it will really satisfy you.
But I don't really understand why the position of the totals is particular in any way especially by an adhoc report. For me it indicates that an user actively worked with the object and with the arrows-keys and/or ctrl + shift + pos1/ende an user could move easily within the object.