Situation test carries 20% weightage in final rank list. It tests candidates material handling and innovative abilty on a given situation and given set of materials. Practice handling all types of craft materials. Focus on making shape with paper, card board etc. Situation test literally tests your imagination and practicality as well.
You need to practice construction quickly as time given will be limited.

You can go through the article given below so that you can get an idea for the situation test.

https://design.careers360.com/articles/how-crack-nift-situation-test