Received this email from GDFL.... Note that brokers will not be affected.
The Exchange (NSE) will be conducting Live trading sessions on 15th and 16th January, 2018, from their BCP site, in Capital Market, Futures & Options, Currency Derivatives, Debt and SLBM segments.
Since we do not have a connectivity at their BCP site, so Exchange will be providing the data from their Primary site (BKC) on a best effort basis with expected delays. It means our data users may experience delayed data and / or data disruption. Users are requested to please take a note and make suitable arrangements.