Minimum Network speed for the webGL, Agora and Photon?
I want want some particular answer or any link from where i can get it
This is a very difficult question.
A simple WebGL Unity game will load even with the minimum internet speed, if there are no disconnections.
The required network speed for Proton depends on the number of clients per room, size and number of messages. You can see an example of calculation on the example of performance tests.
For Agora, not only speed is important, but also that there are no delays (minimum latency). Required Internet speed will depend on how you will use it: voice, video, chat. For example for the video use case, for one-to-one video call 240p (320 x 240, 15 fps) you need - 200 Kbps and for one-to-one video call 360p (640 x 360, 15 fps) - 400 Kbps, but for the chat use case minimum speed will be enough.
To answer your question, you need to know exactly the parameters for using Agora and Proton.