Hi,

For Common Admission Test(CAT), you need 50% aggregate marks(45% for reserved categories) in your bachelors degree from a recognized college/university. Aggregate here means that in your bachelors degree, your overall marks of all the 3 or 4 years should be 50% or more(45% or more for reserved categories). So, you need not to worry that you have scored 48% in second semester. You are eligible for CAT.

For more detailed eligibility criteria exam pattern: https://bschool.careers360.com/articles/cat