Google "NetMonitor" and you can see dozens of titles. I no longer advise one or the offer since everytime there has been some objection. For this I'll note how to find them.
Frankly I feel the better way is to get a router with quotas.
I and my friends have been using the same internet connection at our room.There is a limited qouta of 75GB per month.Is there a way to track how many data has been used up by each one of us?
I think it can been tracked by any software that tracks internet usage by mac address.Not sure such a software is available or not.
If there is any such softwares or a better solution for the scenario please help..