Hello there,
You have scored an overall percentage of 47 and you have passed your 10+2. But, if you sit for the competitive exams, they require a minimum aggregate, else you are not eligible. For example, if you are a PCB student, and want to sit for NEET, then you need to score a minimum aggregate of 50% in physics, chemistry and biology/biotechnology. If you fail to score this marks, you are not eligible. This goes for every other competitive exams. So it's better if you check these and then decide if you have to give an improvement test. You can mention your stream and the exams you are interested in, so that we can provide you the necessary details.
Hope this answer helps you.
Good luck!!