Hi Siva,
If you have derived flows set up then you can do the change. I am not sure what kind of product but i will give example of Money market instrument.
Treasury and Risk Management - Transaction Manager - Money Market - Transaction Management - Flow Types - Derived Flows - Define Derivation Procedures and Rules
you can see all the derivation procedures and by selecting the derivation rule you can create new rule with new effective from date with the new rate.
Hope this is helpful.
Kind Regards,
Chandra