Anna University valuation is known for its standard and quite ambiguous.

When you expect an A grade, you end up getting D/E grade and when you expect a U grade you end up getting B/C and sometimes even A.

Let us here see the experience of a Girl of Anna University who shares her view on http://jobsrecruit.in/anna-university-paper-correction-procedure/ Procedure

I once expected to get a S grade in the first year subject(Academic Year 2011-12) "Fundamentals of Computing and Programming" but ended up in E grade. After applying for revaluation by paying 700 Rupees, my grade improved to C.

Till November-December 2013 examination,the revaluation procedure was different. You need to pay 400 Rupees for evaluating the paper again or you need to pay 700 Rupees for getting the photocopy of the answer-sheet and revaluation done. Many of my friends shelled out money to improve their grades and the efforts were never fruitful.

Hence, I stopped applying for revaluation from the subsequent semester knowing that it would be a waste of time and money.

Another important observation about Anna University correction is that if your handwriting and paper decoration(!!) is good, chances are there for you to get high marks irrespective of the content.

Writing lengthy answers with so many diagrams also fetches marks. Although the standard of question papers is quite good, the Anna University doesn't raise knowledgeable engineers with its poor correction procedure.
Source: https://www.quora.com/