There were a lot of speculations on how much did the Indian intelligence know about how many folks and who all were in the Balakot facilities when the bombs were dropped by the IAF pilots. We were given a figure of close to 300 (including the helpers, staff etc).
Turns out the intelligence on who and how many were there was far deeper. The Indian side also knew who was in which room and how many were there in that room, for every facility within the complex.
It was basis that intelligence that they selected their targets and eliminated everyone inside those buildings.
Although no one is saying whether Masood Azhar was in there or not, but the very fact that the Indian government is more interested in asking for Syed Salahuddin and Dawood Ibrahim now, as opposed to Masood Azhar, shows that there is some knowledge of that he was amongst those 300 who were smoked out!
Here is a detailed report by India Today on the details of the operation. Watch it carefully.
Who was there and where everyone was is a pretty detailed level of intelligence. This just means the inevitable – that India has found a way inside the Jaish camp or some way to keep tab of them pretty closely.