Sorry to say but 55% are very less percentage. You must know that all institutes have eligibility criteria for class 12th marks. All institutes have criteria of 75% marks and some have criteria of 65% marks. That's why to get admission in any good engineering college you must have to increase your percentage in class 12th by reappearing for improvement exam.

Even if you get admission in some engineering college with such low marks, it will effect you in future because poor colleges don't have placements and without that you have to depend on government exams after graduation and for that also 12th percentage is a criteria.

That's why you should appear for improvement exam.

Best of luck