Kerala

Hi Suresh,
It's unfortunate that you have not cleared your 3rd year B.Sc and have landed up a backlog which has delayed your graduation.
You need to contact the institute officials personally for specific admission details as it differs from one college to another. You may also consult your previous college, if they can re-consider your case. I would request you to contact your Head of Department regarding the procedure set forth by the college.
However, you may pursue your graduation via distance or correspondence mode of learning. There may be some difference in Correspondence and Regular course, I would say it varies from one subject to the other also from one degree to the other. However, in general, a course through distance learning does not have as much value as the regular one so if you can do a regular course, it would hold a lot of importance and thus be a much better option. The acceptability and recognition of a full time course is higher in industry and the long term career gains are good.
Correspondence courses are ideally meant for those who are working and cannot leave their jobs to further their education. It is only to leverage ones experience and not so much as a standalone degree. The employ-ability of a full time degree holder is the most and those with a distance education degree may face a drawback as far as employment options with MNCs are concerned. However, what is also relevant is your experience; skills and profile should match the profile needed for the job and organization. Thus, it would be best for you to pursue a full time course.
I hope this information helps. Please feel free to revert.
Wish you luck.