Hi All,
So finally i am able to debug the code, unfortunately still not able to achieve it with visual studio but found the other way around. Posting it to help others.
For debugging purpose, i place=d my code inside a button click instead of onload and downloaded "Microsoft Edge Preview Tools".
1) Open the Resco App, Navigate to the page which has the offline html
2) Open "Microsoft Edge Preview Tools", it will display all the html files from RESCO App. Click on the one to be debugged.
3) It will open Edge Developer Window, Navigate to the file required in Debugging Tab, Place the debugging points
4) Now go to RESCo App and click on the button in your html file, it will open the file in debugging mode in Edge Developer tool.


Hope it helps. Still looking through Visual Studio one, shall post if i find that too.