Hi Krishna,
While rightly summed up by C.B that "language" story is not that simple, you would still like to refer a config step under Report Shipping-->Basic Settings for shipping from SD Documents-->Assign Language & Lead time to country.
Also check the customer exits for report shipping configurations and see their significance in the Report shipping guide by SAP (You can find it in relevant SAP consulting notes on report shipping)
Regards,
Pavan