For your fishery business in a rural area, there is one scheme run by the central government that is Pradhan Mantri Matsya Sampada Yojana (PMMSY). It provides financial assistance, cage culture, and setting up hatcheries. They also provide training.
The Fisheries and Aquaculture Infrastructure Development Fund (FIDF) also provides infrastructure development for your fishery business; through Mudra Yojana, you can apply for the small loans.
To avail yourself of this scheme, apply through the District Fisheries Office with all the necessary documents.