Hello aspirant,
As per your question that is how many months are required for study of semester exams for civil branch according to me there are two categories of students so I will elaborate for both you should go with anyone according to your type.
Type 1 - If you are a regular student and attending every lecture then you have to spend only 15 to 25 days for study of semester exam because as you are learned well all the concepts so you need less time to study.
Type 2 - If you are not regular student and preparing for some other entrance exams like GATE and all then you have to study before 20 to 30 days of exam as you are not attended lectures so you have to study hard in those days.
Hope this information will help you.
Best of luck and Thank you.
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