Well if you were born in the first half of the year and the engineering degree you did was a four year course you could have well completed your course when you are 21. I completed my masters (5 years) when I was 22 but since Niti is born in November, she would have been 20 and a half if she had completed her 3 year graduation (of course as I said if she had gone by normal schooling). Since she was educated in Delhi, one has to have completed 5 years of age to seek admission in Class I, unless of course she managed to get a special waiver. Even if she had managed to get that waiver, she would have been 18 and a half years old when she finished her second year. Since she finished this in 2012 itself as she claims, it would still make her 21 and a half years old, not 20.Anyway, all these are for arguments sake as they say age is but a number. If you look way younger than you really are, it is a huge compliment and Niti most certainly looks like a fresh teen. In fact she hasn't aged since that interview in 2012.