Hello Akshit,
The below links will help you understand the integration and also the steps to do the same. T Codes are already mentioned in the second link. Hope this helps.
http://wiki.sdn.sap.com/wiki/display/CRM/Interaction+Center
http://scn.sap.com/people/john.burton/blog/2009/11/11/how-to-implement-computer-telephony-integration-cti-with-the-sap-crm-interaction-center
Best Regards,
Saurav