Hello Dhinesh,
Try using the BAPI 'BAPI_EXCHANGERATE_GETDETAIL'. It gives correct details.
CALL FUNCTION 'BAPI_EXCHANGERATE_GETDETAIL'
EXPORTING
rate_type = 'M'
from_curr = 'INR'
to_currncy = 'USD'
date = syst-datum
IMPORTING
exch_rate = gs_exchrate
return = gs_return.
You should be aware that there could be an interface that updates the Exchange rates which you may have to run manually to update it in stadard SAP tables to get the correct exchange rates. If not, you have to manually give the latest exchange rates in transaction OC41.
Hope this helps.
Regards,
VIjay.