more or less the same experience as Vishy said.
GD was for close to 15 minutes. The caselet was about an MBA guy who wanted to start Amazon in India, whether it should be an online or a brick and mortar store. It was a moderate GD, with no fish market stuff. Almost everybody got chance to speak something. The moderators asked one guy to summarize.
Immediately after GD they gave the sheet for the personal profiling test. This an area where you can prepare nothing. Be yourself. The sheet gives you a set of 24 questions, each question would contain 4 words, you need to mark the work most suited to your character, and the one least suited. For some questions the majority of the options looked similar to me :).
eg: something like generous, stubborn,considerate,friendly (not exact combinations, i dont recollect the same words

). There is nothing you can prepare for this!!!
The interview was based on the Profile itself. The questions came as and when the panelist flipped through each of the pages.
Be thorough about the work you do, the projects.. you may be asked to explain the work, if you are implementing some formula (where and how did this formula come from) etc.
Some of the other questions to me where the generic stuff,
Why do you want to do an MBA
Why GLIM
What specialisation are you looking for.
Rest of the questions were specific to my projects and my career plans.
Atleast in my PI there were no GK stuff asked to me, but cant take this as a thumb rule,
They dint ask for any certificates, only thing which was verified was you CAT/GMAT score card by the ADCOMM members
Met a few Pagalguys there.. it is a indeed a good feeling to know some of your fellow aspirants... (atleast you get to talk to someone when you are sitting in the hall).
Thanks and kudos to the adcomm members