CHENNAI: Not a single engineering college of more than 500 students in Tamil Nadu has secured a pass rate of more than 90% in the first semester of the 2013-14 academic year. Separately, not one student in 56 colleges has passed all subjects in the first semester.The recently released first semester results of students in engineering colleges across the state show that the highest pass percentage was 87.45%, secured by RMD Engineering College. The list of top 10 colleges with the highest pass rate has some surprises. At least three colleges from districts other than Chennai are among the top five.K Ramakrishnan College of Engineering in Trichy, which was below the 25th rank last year, has the second highest pass percentage this year at 86.07% followed by Sri Sai Ram Engineering College near Chennai with 83.76%. Saranathan College of Engineering in Trichy, which was below the top 25 last year, is in fourth place with 83.21% followed by Ramco Institute of Technology in Rajapalayam with a pass rate of 82.82%.Three institutions belonging to the RMK Group figure in the top 10 list. K Manivannan, professor of planning and development in the RMK Group of Institutions, said they had developed a unique methodology. “We take our internal tests very seriously, and evaluate them by giving dummy numbers and exchanging the answer scripts within the group of colleges. We constantly challenge the students to push boundaries.”D Srinivasan, principal of K Ramakrishnan College of Engineering, said colleges in the districts had now managed to break into the top ranks and stand alongside colleges in and around Chennai by identifying the weak links and working on them. “We get a lot of rural students. They lag behind in communication skills. So, we continuously strive to improve this area, and soon they are able to catch up with the others and perform well in academics,” Srinivasan said. He added that 60% to 70% of students in the college were good performers in school. “This makes our job easier,” he said.Regulars in the top five list, including Sri Sivasubramaniya Nadar College of Engineering and Meenakshi Sundararajan Engineering College, both in Chennai, have dropped to 17th and 18th ranks respectively.Though marks secured by the students alone do not determine the quality of an educational institution, an academic ranking gives a reasonable indication of which colleges lead the pack.