I had answered this recently on this thread
As a trader - I like the idea because there have been so many times when you couldn’t react to US market opening or news that usually comes around that time. As a broker - I like the idea because that would mean more business. But many mid sized brokers may not like this because it would put stress on their operations - like having two shifts for people working and etc.
But yeah, this is a tricky one. If I had an option, I’d keep maybe the Nifty/index derivative trading 24 hours a day similar to the US markets. Anyone who wants to hedge/factor in macro news can then use this instrument.