this works by sify so maybe it should work with 24online which works with lan . Buy a hub put 24online lan cable in it . put 2 cables that connect two other ports of hub to 2 different lancards in ur pc . Configure both with diff ip/mac required ( 24online authenticates with mac i think) . Diable one connection .. start client and login with one id . kill the client from taskmanager .now disable first connection which is logged in and enable the one with other ip . Start client againa nd login other id ( this time it will use other ip ) and then again kill the client ..Now enable both connections and u have 2 lan connections with 2 diff ip logged on net .. use any program like wingate to route connections through both properly . This is just overview many thing depend on how ur lan works . Btw if ur client has an option to select the nic to login then there is no neeed of all that enable/disable hasstle .
don't do anything just install VMware on your PC and share the same LAN with the installed OS on the PC and then conenct to Broadband with the other UserID. you need a very good system. i mean powerful system to run 2 windows at the same time.