The exam, which determines admission to country's prestigious Indian Institutes of Management (IIMs) and many other B-schools, is being held in a staggered online format for the first time. Sunday was day two of the 10-day schedule.
From day one on Saturday, technical glitches and computers crashing prevented the exams from being conducted in many centres across the country.
On Sunday, while the organisers posted an update on their official website announcing the rescheduling of the exam in 49 labs in 24 centres across India, there was no direct communication, either through mail or SMS to the students, creating much confusion.
In many cases, students had reached their test centres when they were told to go back home.
"There was utter confusion. Some of our students called and told me that they had no idea about the exam being rescheduled on Sunday. They reached their centresin the morning and then learnt that the exam was rescheduled. But there was no official who gave them any reason for the change in date," Gautam Puri, vice chairman of Career Launcher, a CAT coaching institute, told sources.
The reason for the rescheduling of the exam, as posted on the CAT-IIM website was "repairs" in those computer labs where the technical glitches had taken place on Saturday.
The unexpected fault on Saturday occurred soon after the CAT examination began in 32 cities, but organisers said it affected only a small number of aspirants who appeared on the first day.
"While a significant majority of the candidates successfully completed their exams on day one, various technical issues arose at selected computers in approximately 50 labs that prevented approximately 2,000 exams from being delivered. Prometric has generated new appointments for these individuals and they are in the process of being contacted through SMS and email messages," the announcement on www.catiim.in said.
The US firm Prometric has developed the computer system for CAT. The company and the CAT committee said the test had been mostly successful.
"Prometric technicians have been dispatched to address these isolated problems. To avoid candidate inconvenience and to allow for the necessary repairs to be completed at the impacted labs, Prometric has scheduled a closure of these labs onSunday, 29 November 2009," the website said.
Among the cities where the exam has been rescheduled on Sunday are Delhi,Mumbai, Bangalore, Kolkata, Varanasi and Bhopal.
Students, however, complained that the last minute update on the website did not help.
Said Rajesh Sharma, a student here: "If only a few test centres were to be non-functional on Sunday, then those students should have been informed. An SMS or mail would have sufficed. CAT is not the only exam we are taking, there are other entrance exams too and all this confusion not just wastes our time but is also frustrating."
Puri added: "This is a case of mismanagement, lack of planning and implementation. There are approximately 150-200 students taking CAT in each centre and that is not such a heavy number local servers can take that load easily. There was no proper testing of the online version of the exam."
Around 240,000 students have registered for the CAT this year, which is scheduled at 105 centres in 32 cities, all linked to a main server.