One of the key disagreements is in sharp focus now: Either women are averse to engineering (due to whatever reasons, including their parents' old-fashioned ideas) or they aren't.
Observation: Women constituted just about a fifth of all JEE takers in 2006; this fraction was even smaller in 2005!
May be women don't like engineering. May be women don't want to pursue engineering. Their social conditioning and their parents may conspire to make them view engineering as a less than desirable career to get into. This is a rough paraphrase of Vivek's point, which seems to find quite a few takers. If this is true, there's nothing IITs can do except to wait for the society to unscrew itself. [Update: This paragraph was edited to reflect Vivek's views better. See his comment below.]
Here's a different view (mine!): while women may not be applying for JEE (for example, they have given up on the IITs, due to their past (abysmal) record of admitting women students!), they do get into other engineering colleges in large numbers. So, this 'aversion to engineering' is a myth.
Well, I don't have the numbers. But, I do have wonderful readers, and I know many of you went to engineering colleges. So, can you please -- please, please -- help us resolve this issue? All I'm requesting you to do is to leave a comment with the following information: the college name, engineering discipline, year of graduation, the number of women, and the number of men.
Many thanks in advance. Here's some example data for my class (just to get this exercise going):
IT-BHU -- Metallurgical Engineering -- 1985 -- 0 women -- 25 men.
Yeah, I know, IT-BHU took -- and still takes -- students through JEE. I will let you decide where the bias was! If you comment under your real name, I promise to buy you a drink the next time you are in Bangalore ...