The IIT-Bombay zone has once again trumped other zones with maximum number of students clearing the JEE (Advanced) test for admission into the IITs, while the IIT-Guwahati zone under which Bihar, Jharkhand and seven north-eastern states fall has again lagged behind.

According to the published results, only one candidate, city boy Ishan Tarunesh, has figured in the top 100, while there is no candidate from the Guwahati-zone in the top 10. Similarly, there are only 10 candidates from the zone in the top 500.

From the Guwahati zone, 2,468 candidates have qualified in the test as compared to 8,810 candidates clearing the test from the Bombay zone, including IIT topper Aman Bansal this year. Last year too, IIT-Guwahati zone results were poorer compared to the seven other zones. Last year too, the only solace for the Guwahati zone was Patna boy Ayush Ranjan, who had clinched the 94th position.

However, unlike last year, the number of candidates clearing the JEE (Advanced) test from the Guwahati zone this year is more than that in 2015. This year, 2,468 candidates have qualified in the test, while 1,445 candidates had cleared the test in 2015.

Those connected to the academic circles feel one of the prime reasons behind Bihar students performing poorly in the IIT-Advanced exam is the brain drain of bright students from the state to the IIT coaching hub cities in other states.

"In the last few years there has been an exodus of good students from Bihar to Kota, Hyderabad, Delhi and other cities for IIT and medical preparation," said Bipin Kumar Singh, the director of Goal Institute, a city-based IIT coaching class. "After completing their Class X studies, these students migrate to other cities to take admission in schools. Their entire focus remains on coaching studies. As students from Bihar or Jharkhand fill up IIT-JEE forms from Kota or Hyderabad, they are registered as students from those zones."

Riya Singh, the topper among girls in this year's IIT-Advanced test who secured the 133rd rank, hails from Chhapra in Bihar. Riya, daughter of Jai Shankar Prasad Singh and Sobha Singh, did her elementary schooling from different parts of Bihar but appeared for her Class XII from DAV Kota and did her IIT preparations from coaching institutes in Kota.

"In cities such as Kota, Hyderabad and Delhi, there are many coaching institutes where good students from across the country study," said Ishan Tarunesh, who has secured the 33rd rank.

"It instils a sense of competition among the students. The students studying in such institutes in Kota and Hyderabad are more focused in clearing the test than other cities like Patna." Others said another reason behind Bihar students faring poorly in the IIT-JEE test is that school education, especially in the Bihar School Examination Board, has deteriorated in the state.

"The main reason behind Bihar students' poor performance in IIT-JEE and other competitive examination is that in the past decade, school education in Bihar has worsened," said Saurav Kumar, a teacher at Vidyamandir Classes, an IIT coaching in Patna. "Government schools lack quality teachers and if a student's base is not strong, he cannot be expected to bring good results by studying in any coaching institute."

A teacher associated with a coaching institute attributed the poor quality of teachers, who are lowly paid, and the low success ratio of the students to gimmicks these classes resort to - fee waiver to the first 100 students taking admission and scholarships for example.