Starts out with an aptitude test ( for college recruitment only). Shorlisted candidates are then asked to give their technical interview, in which all kinds of technical questions are asked, based on the candidate's specialization.
From here, selected candidates are sent to the Management round, where they are tested to see how effectively they handle high pressure situations or respond to criticism. A thick hide and a quick mind will get you through this.
Finally is the HR round, where you are briefed about the company policies, and you may have a GD at this part. This is just to ascertain your ease of communication.