Hi Suma,
There are various methods apart from job portals to source the potential resources.
Kindly find below few of the headhunting and networking methods
1. Project mapping - Map projects related to the technology. For example, you are working on mainframes requirements, Kinldly make a list of companies working on the mainframe technologies, their client for whom there are working, Domain, city where the project is carried etc.. on the basis of that, when you require a resource for company A( Project is in BFSI Domain, CLient is M, Location is ABC), find similar companies working with the same client M. In that way, you could generate resources.
2. Get references - Getting references would really mean a lot. You make a habit of getting atleast two references of any skill set with each candidate you speak. Maintain a excel sheet so that it would be really helpful.
3. Social networking sites - Build your network in social networking groups and maintain a healty network.
4. Headhuting - COllecting the board numbers and making cold calls.
5. Get references from the candidates whom you have already placed. Keep a positive and healthy relationship with him, So that he would refer your name to their colleagues when there are in a need of job shift.
These are the few methods apart from portals, which would help you in generating resources. Trust me, in all these methods, the duplication ratio is comparitively less than profiles sourced for job portals.