Level 3 ,20 Depth websockets Data

where to get Level 3 Data web Sockets data ?
how much its costs ? seen rates in nse site, i am talking about data brokers to end users .
also read NSE is not allowing zerodha to provide Level 20 Depth to its api users , why can’t they allow it ,they were okay to display in web Platform .both web or any other platform app ,uses same sockets/Data connection .

candle api allow level 2 data now ?
or we can get level 3 data stream now with api ? any updates regarding that ?