Hello student,
How to say you but actually you have not clearly mention that whether you have not past total 6 semesters or weather you have not pass the 6th semester. So basically in both cases you only have to clear your backlogs on the papers you could not reach the pass marks which is general 35% marks for graduation, but it differs from college to college. If you parcing a 3 years long undergarted degree course then having a backlog in 6th semester may causes delay in placement process and also if annot get into another colleges or next level of your study until your this backlog is get cleared . Hope this help you