NIFTY JAN-14 Series.
NOTE : Those who are using OAT, and trying to look the Option chain values for FEB-14. Normally the Expiry for a month is on the last Thursday of the month. But for some reason the FEB-14 Expiry is 26-FEB-14 (Wednesday) instead of 27-FEB-14.
The Next three months Expiry dates is got from the Sheet "SODATA" from the cells AP20, AP21 and AP22. So you might have to hardcode the AP21 to 26-FEB-2014.