No, not having prior knowledge of Japanese won't necessarily be a problem for applying to BA Honours in Japanese at Jawaharlal Nehru University (JNU) or English and Foreign Languages University (EFLU).Both JNU and EFLU's BA Honours in Japanese programs are intended for students with no prior knowledge of the language.

The first year curriculum typically focuses on teaching Hiragana, Katakana, and basic Kanji characters, along with fundamental grammar and pronunciation.

https://www.careers360.com/university/jawaharlal-nehru-university-new-delhi

Hope it helps!