Hellow,
I want to participate in a robotics competition. What kind of projects
I can consider? & also on what sites could I get the info?
Please suggest something.

Different competitons will have varying acceptable types of projects. Robotics is a hot item, so plenty to be found on the net; just browse a bit until something that excites you (and is acceptable for the competition(s) you want to enter) catches your eye:

Robotics Project Ideas