Amoj Jacob gained his first international experience in 2016 at the Junior Asian Championships in Ho Chi Minh City , where he won the gold medal in the 800-meter run and the silver medal in the Indian 4-by-400-meter relay. He then took part with the relay at the U20 World Championships in Bydgoszcz , Poland , where he finished seventh with 3: 09.14 minutes. In 2017 he won the gold medal with the relay at the Asian Championships in Bhubaneswar and took fourth place in the individual competition over 400 meters. With the season he also took part in the World Championships in London , but could not qualify for the final there . Two weeks later, the student from the University of Delhi took part in the Summer Universiade in Taipei , where he retired over 400 and 800 meters in the first round and finished seventh in the relay in the final. At the beginning of September at the Asian Indoor & Martial Arts Games in Ashgabat, he finished fifth over 400 meters in a new Indian indoor record of 47.33 s.
In 2018 Jacob took part in the Commonwealth Games in the Australian Gold Coast for the first time and could not finish his race with the Indian 4 x 400 meter relay in the final. The following year he took part with the relay at the World Championships in Doha and was eliminated there with 3: 03.09 min in advance.