Hello Ketan,
Indian Maritime University conducts IMU CET exam for admission to for admission into the various courses offered by the campuses of the institute.
According to IMU CET 2019 eligibility criteria, candidate should have qualified class 12th examination with aggregate marks of 60% in Physics, Chemistry and Mathematics.
Also, atleast 50% marks should be secured in English.
Since you have scored 58% in physics, chemistry and Mathematics you just need to score few more marks to be eligible. You can appear for improvement in one or more subjects in which you have scored less marks. Also, you can appear for improvement in the subject in which you are more confident and can score better marks.
It depends on you to appear for the improvement exam in one or more subjects.
Good Luck!