Judge Verma is a very strict man whose judgments sometimes seem unusually harsh. One such instance is when a man named Shankar Yogi is brought to his Court charged for rape. Yogi protests that he is innocent, but the judge says that Yogi's record is so bad that he cannot be believed. To the judge, children of criminals also become criminals, crime being a matter of bad blood. Yogi says that Verma will pay for this decision. After completing his imprisonment Yogi kidnaps Verma's wife, who unknown to even her husband, is pregnant. When Yogi comes to know this, he knows how he can take his revenge. He creates a misunderstanding between Verma and his wife - Verma thins that the child is Yogi's and throws his wife out when Yogi sends her home. She wants to kill herself but Yogi saves her. She delivers child - a girl - and Yogi takes care of her, even when Judge Verma's wife dies. Years pass.
The judge's two sons Kunal and Karan have grown up now, Kunal is a sober and hard working man and he takes care of his factory. Karan is a playboy who falls in love with an ordinary girl, and when Kunal cannot accept her, Karan leaves home.
Meanwhile, Yogi meets Kunal and tells him that he has a sister Tina, who has become a shore and is now in complete control of Yogi. Kunal cannot believe this at first - but when he does, he wants to rescue her. He is injured when he tried this and is hospitalised.
And it becomes Karan's duty to rescue his sister, whose existence he comes to know only now. And his mission becomes even more difficult because his sister hates her family.
How the brother's succeed in their seemingly impossible mission forms the climax of "Pehchaan".
(From the official press booklet)