I use the first link. The Second link is a general link which has the syntax for the Futures also.
The problem with the both the links that the expiry date is not explicitly mentioned and so a bestfit will be found.
So better to specify the Expiry date explicitly as below
Code:
http://www.nseindia.com/live_market/dynaContent/live_watch/option_chain/optionKeys.jsp?symbol=NIFTY&date=30OCT2014
BTW both the links showed me only 7884.25