With 300 marks in KEAM and an Ex-serviceman reservation, your rank will likely be better than general candidates with similar marks. While exact ranks vary each year, you can expect a rank between 10,000 to 20,000. Your reservation will help you get a better chance at government colleges, especially in branches like agriculture, fisheries, or lower-demand engineering streams. Keep checking the official KEAM rank list and counseling updates for your exact position and college options.