Trending @HCL; Rating vs Assesment score

The final rating could be of many factors... I know a colleague avg score is 8.7 but final appraisal review closed with Threshold performance.
The justification my colleague received was due to client feedback . So, if all is good the final appraisal will be aligned to the avg score else if any deviation whatever your score might be you'll land into some other rating

Last year I had DP, and 0% appraisal

Yes it can be changed if your DU head agrees .