Hi Vyom,
I'm afraid your issue may be more basic than that - Marketo generally has issues picking up changes with SFDC formula fields as when they change they don't "modify" the field they are in, or the modtimestamp field in the record itself, so Marketo will skip over them and not see that there has been a value changed at all.
Generally these need other fields on the record to be updated, or some kind of update to another field done via Apex trigger to make this work. There's a lot of discussion on the community around dealing with SFDC formula fields.