Jio Fiber cc had no clue to upgrade Netflix plan.
Also I did try through Netflix website but it changed my billing plan altogether from Jio billing to Debit/Credit card billing as I got debited for full 799 amount. I called up Netflix cc, they cancelled my subscription and reversed complete amount.
They told clearly the upgrade needs to happen through Jio else I will be charged full amount and not the difference.
Now I am left with no Netflix although my Jio subscription shows basic plan.