How to track renamed symbols

https://www.just-food.com/news/indias-lt-foods-buys-back-daawat-foods-stake-in-salic-saudi-arabia-partnership/

I checked the instrumentlists for today and found the instrument token for LTFOODS which is 3536897.
Then i used Linux cli tools to search through last few months instrumentlists and this is what it returned

./instrumentslist_20230101.csv:84088:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20230102.csv:84166:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20230103.csv:84511:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20230104.csv:84551:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20230105.csv:84880:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20230106.csv:85382:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
...
...

./instrumentslist_20231101.csv:88539:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231102.csv:88972:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231103.csv:89640:LT FOODS,3536897,13816,0.0,NSE,DAAWAT,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231104.csv:90925:LT FOODS,3536897,13816,0.0,NSE,LTFOODS,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231105.csv:90925:LT FOODS,3536897,13816,0.0,NSE,LTFOODS,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231106.csv:90926:LT FOODS,3536897,13816,0.0,NSE,LTFOODS,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231107.csv:91362:LT FOODS,3536897,13816,0.0,NSE,LTFOODS,0.05,0.0,EQ,NSE,,1
./instrumentslist_20231108.csv:92080:LT FOODS,3536897,13816,0.0,NSE,LTFOODS,0.05,0.0,EQ,NSE,,1
...
...

So as per the news article LT foods bought out the other shareholders in Daawat foods and then the symbol changed to LTFOODS from 4th November onwards though the instrument code remained the same.
I havent checked the NSE bhav copies for the same period but I think the same would reflect in the bhavcopies too.

Now for your question about how do you track these changes, there is no api or automated way to do this.
You would need to write your own code to alert for new entrants or changes to the listing details.

I maintain historical copies of bhavcopies as well as instrument code in csv format as well as a database and in those databases for the bhav copies the ISIN is the primary key and source of truth. For the instrument list db the instrument token is the primary key and source of truth. And I have a separate mapping for instrument code to ISIN mapping.

Once you have system like this you could build your own change reporting tools.

@spartacus Glad to help.
Please also note that any change tracking logic will only apply to fundamental/spot instruments on the NSE and BSE and not derivative instruments (FNO) . The instrument tokens for derivative instruments could be recycled over time.
And I am not sure at all about how the logic would work for other instrument categories like Mutual funds, Currency and Commodities.