Hello,

The eligibility criteria to appear for UPSC is as follows;

• candidate needs to attain 21 years as on 1st August of the appearing year,
• passed graduation in any discipline from a recognized university, those in the final year of graduation too are eligible to apply, there is no minimum aggregate required here,

Bachelor of Fisheries is an undergraduate degree for a duration of three years, and  UPSC accepts any relevant graduation degree, as long as the degree is done through UGC recognized university it's definitely valid and to answer your question you can surely appear for UPSC.