The following thread is quite informative :
http://www.pagalguy.com/forum/career...e-testing.html (software testing)
I think you need to be clear on certain things first. "Testing" as a career is way too generic and you claim they have put you into "Siebel technology".
a) There is no such thing as "Siebel Technology" ( or that maybe their terminology for the language in which Sieble was developed ).
Siebel is a Customer Relationship Management (CRM) Product currently "owned" by Oracle ( Is that your MNC? ) . I really don't see much development going on in that product (I know some core people who are/were in charge of it from India. But don't quote me on it though

) ) If I were you I would ask the HR to
clearly tell what kind of work you will end up doing ( Not that I expect them to have much idea about it or even if they do be honest about it but is at least worth a shot!
b) The kind of work a "tester" would do in a Product company is largely different from that of a software company. Having worked in both and been actively involved with the testing team and process I can vouch for that.