Having seen the posts above I had to intervene for a few things GD 1) Never talk non-sense in a GD 2) Having knowledge about the topic helps and if you do then you can start. Be 1st or second. 3) Don't interject anyone abruptly 4) If you don't know about the topic "LISTEN" and then contribute. 5) Confidence matters but SUBSTANCE is key.
PI 1) Know YOURSELF. Why are you sitting in that chair? 2) Be clear, concise and confident 3) Sometimes losing an argument can win you interviews so don't be adamant beyond a point. 4) Know about your interests thoroughly. Have few interests but in depth rather than shallow knowledge of too many interests/hobbies 5) Be attentive and LISTEN to the questions. Don't hesitate to ask the question again.
Off course work-ex of any kind helps. But be sure that you know about your job like noone else does.
