The NEET PG percentile score represents the relative performance of a candidate compared to all other candidates who appeared for the exam. It indicates the percentage of candidates who scored equal to or below a particular candidate. For example, a candidate who scores in the 90th percentile has performed better than 90% of the candidates who took the exam. The percentile is not the same as the percentage of marks obtained. It is calculated using the formula: Percentile = [(Number of candidates who scored equal to or less than the candidate) / (Total number of candidates who appeared in the exam)] × 100. The percentile score is used to determine the qualifying cutoff for different categories such as General, OBC, SC, ST, and PwBD.