In the men's lightweight double sculls, India's Sandeep Kumar and Manjeet Singh finished last in the six-team repechage round to end any chances of a podium finish.
Swarn, who made it to the quarterfinals after competing in the repechage round, clocked 7:11.59s in the 2km race.
The 23-year-old rower from Punjab was running second in the first 500m but lost steam later to end at the fourth spot far behind the top three finishers. He will now compete for 13th to 24th positions.
Lassi Karonen of Sweden won the race in 6:57.06s while Santiago Fernandez of Argentina and Liang Zhang of China were second and third respectively with timings of 7:01.57s and 7:02.03s.
Meanwhile, Sandeep and Manjeet clocked 6:54.20s over the 2km distance to finish sixth in the lightweight double sculls repechage round and will now compete for the 17th to 20th positions.