Hello

the best mark will taken into consideration. if you fail then your 56 marks will be considered. Improvement exam is done to give a chance to students to improve their score. The high score will be considered from the both.

Don't think about all these and prepare for the exam. Try learning the concepts and know how to solve the numericals. this will make you able to solve the numericals in more easy way and understand it. With out understanding, you will get confused and get wrong answers.

Hope it helps!