There's a rule called 3.5% rule that says for a movement to topple any ruler, even the harshest dictator of all, an engagement of 3.5% of the population is enough, and that many people never failed in history in bringing in a change.
So talking about Pakistan [not BD]
How many should this ongoing Azadi march attract to succeed? With a 200 million population it gives a number of 7 million. Otherwise hope for the military to intervene.
Watching.