In this research study we reported the results on the employee core competencies influencing the evaluation performance appraisal system using multiple regression analysis with reference to Agriculture Research Institutes employees in Hyderabad Metro, India. The primary data were collected from the performance appraisal forms of 400 employees working in the agriculture research institutes in Hyderabad, India consisting of from 300 men and 100 women employees. The seven independent factors, Job knowledge, Skill level, Job execution, Initiative, Client Orientation, Team Work, Compliance to Policies and Practices, one dependent factor outcome of the Performance Appraisal System (PAS), the Rating were measured. The descriptive analysis, correlation techniques and parametric statistics like t-test and multiple regression analysis were carried out to arrive at the conclusions. To measure the reliability of the scale used for this study, and internal consistencies of the instrument, the reliability statistics-Cronbach's alpha (C-Alpha) was estimated. The overall C-Alpha value is 0.91, and the C-Alpha values for all the factors ranged from 0.81 to 0.89, whereas overall Spearman Brown Split-half is measured at 0.88. The multiple regression analysis reveals 74% variance observed in this model and except client orientation all core-competencies are influencing the model and outcome of the performance appraisal outcome-the Final Rating.