AMFI publishes the NAVs of every Indian Mutual Fund scheme on it’s website at this link http://www.amfiindia.com/spages/NAV0.txt. Gnucash picks the NAV prices from it.
When you access the above AMFI NAV file, you will find it’s structure as follows:
107636;INF204K01844;-;Reliance Natural Resources Fund-Growth Plan-Growth Option;9.2788;9.1860;9.2788;11-Jun-2012
107636 is the symbol for Reliance Natural Resources Fund-Growth Plan-Growth Option. This matches with the symbol we used to set up Gnucash to enable us to retrieve the NAV of the above Mutual Fund.
Once you have got the symbol codes, you can see how to set up Gnucash to use them.