Hi Radha, generally there is no fixed score for percentiles or any concept like that. It varies everywhere based on the number of appeared students and toughness of the paper and many criterias. Generally as per the previous records, a score of 150 can yield a minimum of 80+ percentile. Generally a score of 180+ yields a percentile of 95+ and a score of 160+ yields a percentile of about 90+. Generally percentile is something which tells how much students have scored less than your marks. All the best