NEW DELHI — For more than half a century, one aptitude test has determined the self-esteem, future and even the spouses of generations of Indian adolescents, chiefly boys. The Joint Entrance Exam of the Indian Institutes of Technology is a brooding cultural force that is visible across the nation, on signboards and newspaper advertisements, as “I.I.T.-J.E.E.,” the first abbreviation many Indian children learn. It is an ominous inevitability for millions of boys, a fate decided in their cradles, a certainty like death. Last year nearly half a million candidates took the test — one of the toughest exams in the world — to compete for about 5,000 seats in the best of the I.I.T.’s and nearly as many seats in the less sought-after institutes. Coaching for the J.E.E. is an industry valued at billions of rupees. There is so much demand that some coaching classes have their own entrance exams. But the J.E.E. is now on its way out.

It is not the only engineering entrance exam in India. Lower down the rungs, there are other colleges, which require other exams to qualify. Competition is fierce all the way. Disturbed by the number of entrance exams, the Human Resource Development Ministry has decided to devise a common exam that would govern the admission process of several engineering institutes, including the famed I.I.T.’s. The nature of the new aptitude test, which is expected to debut in 2014, would be different from the J.E.E. The selection procedure, too, would be very different from what the I.I.T.’s use today. So, the type of person who enters the I.I.T.’s in the future may be very different. Opinion is divided on whether the new I.I.T. graduate will be better or worse than current alumni.

The I.I.T.’s are nothing without the national perception of the “IITian.” And the perception is that he is primarily a he. And that he must be very smart. As some Indians point out with a hint of pride, in Scott Adams’s “Dilbert” comic strip, the brilliant Asok, who died on a Moon mission and reincarnated as part man and part Snickers bar, is from I.I.T. The fame of the institutes is an enduring relic from the years when socialism impoverished India and securing an elite engineering degree became the most elegant way for smart Indians to escape to America.

The I.I.T.’s were never great centers of learning by world standards.

Rather, they were museums that collected young Indians with excellent quantitative abilities. In the 1980s and ’90s, the migration of Indian scientific talent to the United States, deplored here as a “brain drain,” became a subject of intense debates in schools and colleges. Once, during the convocation ceremony at I.I.T.-Madras, the chief speaker received a standing ovation when he declared, “Brain drain is better than brain in the drain.” His words traveled with the speed of a rumor across Madras, also known as Chennai, through homes and schools, evoking laughter and applause, and delivering a bleak reminder to young boys that their lives depended on passing the J.E.E.