Sorry guys.. did not give any update for the past two days..
But finally it worked... :-)
as "edziu15" mentioned initally i tired to configure the dialup connection and was searching for the ISP user name and password as i dont know.

After some googling i came to know that its the mobile no for both user name and pwd.

But with this configuration it didn't work.. then i tried googling again about the possible problems then i found some interesting information about the advanced properties for the modem where some string is mentioned in "Extra intalization commands" i tried with some string which is there in the net finally it works.... i was getting the decent speeds....

Thanks guys for your help...