hi,

the eligibility criteria to appear in gate exam is, candidates have to complete 4 years bachelors or three years bachelors course in relevant discipline or in final year of bachelors or m.sc course are eligible to apply.

now coming to your stream, there is n specific papers available for fire and safety engineering according to gate 2021 syllabus, which is provided at below link:

https://gate.iitb.ac.in/papers.php

however candidates are allowed to appear in gate exam from any of the stream irrespective of their bachelors course stream. so you may choose any of the papers which may close to your stream.

hope you understand.