Passport status- nationality is doubtful.

Hello.. My name is kiran and my parents are from nepal but i was born and brought in delhi on 5/12/1997. My father is staying in delhi from last 34years . I did my schooling and college from delhi. I wished to study abroad and i applied for the passport for the same but my passport status shows my Nationality is in doubt. I have all the IDs for the requirement except passport. I am trying from a month to get the RPO appointment online but it's not happening. I don't know what to do ? Where to go and ask ? I was born here and i love this country so much, i never felt like outsiders before but this totally sad for me . How can i prove my nationality to them .Please if anyone can help with that question.