Predicting an exact percentile for a specific JEE Main score is difficult, as it depends on several factors that vary each year. These factors include the overall difficulty of the exam, the number of test-takers, and the performance of all candidates in that particular session. However, we can provide you with a general estimate based on past trends and common analyses.

To understand how marks translate to percentile, it's essential to know that percentile reflects your relative performance compared to other test-takers. For instance, a 90 percentile means you performed better than 90% of the candidates. Therefore, a raw score of 66 marks will be converted into a percentile based on how other candidates performed in the same shift and across all shifts.

Based on past JEE Main trends, a raw score of 66 marks generally falls within the range of approximately 80 to 85 percentile. This range is an estimation, and the actual percentile might vary. This means that if you scored 66 marks, you likely performed better than 80 to 85% of the other candidates who took the exam.

Keep in mind that the National Testing Agency (NTA) normalizes scores across all sessions to account for variations in difficulty. This normalization process influences the final percentile. Therefore, your percentile might be slightly higher or lower than the estimated range.

To get the most accurate percentile, you'll need to wait for the official NTA results. After the exam sessions conclude, NTA releases the final scorecards containing the normalized scores and corresponding percentiles. Until then, you can use the estimated range as a general guideline. It is important to remember that these are estimations, and that the NTA's official results are the only definitive answer.