How many prop trading desk are active in india and all over the world?
For India, a way to identify this could be by using exchange reports. Typically as all Prop desks have their own broking licenses, hence you can refer to this report (Member proprietary positions & margins) on the NSE website to find segment wise list of trading members that utilize all their margins for prop activity (mainly 100% of open positions and margins only being utilized for proprietary trading purposes). This report is updated on a monthly basis.