How to use two internet connections in same computer?

[Eric]

its tricky but you can set up a server for the TATA connecting all the computers in the office to that, requiring a login for the use of internet and file sharing for each computer.
your is easy, you default the BSNL as your default internet connection, and log into the TATA server when you need to. resulting in it turning into only a file sharing connection because you still have the BSNL active
if i am correct it should work
in my opinion i agree with the guy above me...i would jsut turn the BSNL connection into the server and use that, makes thing less complicated