In GUNCash INR currency symbol is showing by a question mark('?').
How to show ₹ symbol in this ?
USING Version: 2.6.18 Windows: 8.1 Pro
I got the temporary solution for this.
Go to Tools --> Security Editor --> Currencies
Just put the symbol '₹ ' along with a space.
If you put only '₹' symbol, it will become '?' symbol after save.
May be it is an issue, and should be logged here...