For details regarding marks vs rank go through following link;

https://engineering.careers360.com/articles/kcet-marks-vs-rank

The allocation for agriculture was closed around 1000-1200 rank in 1st round. So, you have very tough chance to get a seat for B.Sc. agriculture.

The allocation of seats depends on cutoff and it depends on various factors like;

• The difficulty level of the exam
• Marking scheme
• Number of candidates appeared
• Number of available seats
• Seat reservation of various categories
• Previous year cutoff ranks/marks