Nsefetch() retrieves data for only FNO enabled scrips

nsefetch('https://www.nseindia.com/api/equity-stockIndices?index=SECURITIES%20IN%20F%26O') 

returns data regarding only scrips enabled in derivatives. How to retrieve data for rest of the scrips?

You need to find the correct URL mate.

Checkout the documentation → https://unofficed.com/nse-python/