In the movie Te3n, the child that is kidnapped is around six to eight years. Then how is the movie named teen? Is there any other logic for this title?
The answer is you are confusing Te3n with teen (teenager).
But Te3n in the film title refers to तीन (Hindi word for number 3 and pronounced as teen/theen). Even the film has three major characters played by Amitabh Bachchan, Nawazuddin Siddiqui, and Vidya Balan. So the title refers to their conflict and journey.