Psychological Tests are simple and for these tests you need no preperatoin. Just be yourself and honestly give answers to questions.
On the first day there will be only written tests like sentence making and simple puzzles. Remember that you cannot complete them in the given time, just feel easy and attempt as much questions as you can.
On the second day there will be group discussion in Urdu and then in English. Topics will be given to your group, first in Urdu and then in English. All of you will have to discuss them for 8 minutes each, by sitting in a half circle. Any one can initiate the discussion but remember that you must speak with confidence and reason. There is no need to initiate the discussion if you don't have any knowledge about the topic. Just listen for a few moments to other members of your group, form a comment in your mind and then speak about it it.

Our topics were:
1) Agar British Hum Per Hukoomat Na Kartay To Aaj Hum Itnay Pasmanda Na Hotay.

2) Internal Discord Is More Dangerous Than External Aggression.

After group discussion you will be given an administrative problem. You will have to study it for 15 minutes and write down your recommendations and decision on a blank paper. Then you will call a meeting, discuss the problem with all of your group members as if they were your sub-ordinates and finally take a decision about the matter. You will have to wind up the meeting in 8 minutes.

And finally you will be interviewed by the psychologists about your personal life and problems.

During the tests, just be yourself, avoid artificiality, act naturally and confidently.