بسم الله الرحمن الرحيم
It is recorded in Bahishti Zewar: Mas’ala 1: It is sunnah to grow one’s hair on the entire head till the ear lobes or slightly below them. If a person wishes to shave his head, it is sunnah to shave the entire head. It is also permissible to merely clip the hair. However, it is not permissible to clip all the hair and leave the front portion long, as is the fashion today. Similarly, it is also not permissible to shave a portion and leave another portion long. From this we deduce that it is not permissible to sport the babri hairstyle (or to cut the hair in the shape of a cap or to shape the front part of the hair).
(Bahishti Zewar, Volume 11, p: 115, Tatimmah Akhtari Bahishti Zewar Chapter 81. Rules Concerning Hair)
Allah knows Best!
Darul Uloom Deoband