It depends on the college where you're studying whether it is private or government . Due to semester based and FFCS system, most of the private colleges have this feature that you can write your exams again in the next year along with that year's examination. You only have to attend college for some time and you can appear for exams. But in some government or any affiliated colleges, it is not applicable as these colleges are under any particular board which have its own rules and regulation.