Hi Siddu,
By default all the standard PS reports shows the values in Controlling Area Currency. In some line item reports like CJI3, CJI5 etc you have the option of selecting Object Currency or Transaction Currency along with Controlling area currency.
In your scenario all your PS reports or reports otherwise will show all the values in CO. Area currency which is INR. You can do postings in AUD, USD , EUR etc to your projects. This doesn't impact anything. The system will calculate the corresponding INR values for these postings based on rate types maintained in system by your FICO consultants whether M or P.
Hope it helps you..
Cheers
Sammar