Ok, this is going to get a little graphic here, but how could Milind not know that its not Prachi's child.
Let me explain, Milind and Prachi had sex right? Yes, I am using very bland terms.. but anyway, if Prachi were a virgin till then, Milind would have known.. I mean, when a woman has sex for the first time, her hymen breaks and she bleeds a little. And Milind would have automatically known from their "experience" if Prachi were a virgin before or not. And if he really believed that it was her kid, well, she couldnt have been a virgin. So you see, it doesnt match up and that for me, is the greatest proof ever. Not stupid DNA reports.
Seriously, how could he not know?