Is it possible to get a broker neutral NEST APIs, were i can opt brokers myself in my setting as my listed broker in my utility.
APIs are built by Omnesys for their terminal NEST. Functions that you'd be able to use vary from broker to broker. Order execution APIs are offered by many brokers(excluding the order status function) but market data, account information APIs are not offered by many (Zerodha offers them). Once you build something, you won't have to re-build if you change your broker, just that the new broker has to offer that function call. So, the best person to go to is your broker.
I don't exactly know how broker neutral platforms work. But if you can select a broker of your choice in settings, I don't think there's any platform that offers that in India. Omnesys is in a position to offer something like that (since many brokers offer NEST), but don't know what's holding them back. May be regulations, may be their strategy.