Please give me some idea, How many meeting can be done concurrently ( at same time ) ? What would be the maximum number participants in each meeting. ?
If on the public instance at meet.jit.si, 100 is the maximum number of participants in a meeting. Understand though that after about 35 users, you may experience a slight degradation in performance (not sure if this is still the case actually because there’s been a lot of performance improvements lately). There is no limit to the number of concurrent meetings you can host.
On your own server, it all depends on the resources you make available. You can run as many concurrent meetings as your server and (most especially) bandwidth can support. There have been reports of people hosting up to 150 participants per meeting (improvements are being made to raise this number to 500). You would need to deploy multiple videobridges though to support the load.