Hello,

The answer key is provisional, it is not the final answer key.  The provisional answer key will be revised before the declaration of final results. If there are any changes in it then final answer key changes and the score is going to change. So the actual score sometimes is going to be 1-3 marks lower or higher than the score indicated in the response sheet/answer key. To qualify in AP ICET or TS ICET you need to score minimum 50 marks out of 200 marks that is 25% marks. As you have said that after checking the answer key your score is found to be exactly 50 however, this is not the final score. Your actual score might be less than 50 marks thus you haven't qualified.