Below benchmark grading

Please post the complete facts.  Performance appraisal comprise of the assessment by the Reporting as well the Reviewing Officer. Which is the Officer  changed - reporting and reviwing officer? Is there any supporting assessment/remarks made by the said Officer in the 'Pen picture' ?

In the apparaisal system, there is a provision for appeal. You may prefer appeal within the time permitted and seek revision of the marks.  Please remember that awarding appropriate marks is the prerogative of the appraiser which cannot be questioned excepting through appeal system.  Even if you try to take legal action, it would be  moving heaven and earth as you have to prove motives for your appraiser to give you lower marks. I do not think you can prove the case.

What prevents you from providing the information? The marks in overall assessment is composite of the assessment given against various aspects inherent in work out put, personal attributes and functional competency as well the 'Pen Picture'. Unless you forthcoming in sharing the information, no meaningful suggestion is possible.