The list of NSE companies can be downloaded from nseindia.com, see:
https://www.nseindia.com/market-data/securities-available-for-trading
Now depending on data source that you are using you may need to add appropriate prefix/suffix. For example for Yahoo Historical you need .NS suffix for NSE
I added that and attached is Yahoo Finance ticker list for NSE:
NSE_Yahoo.tls (18.6 KB)