Indian mustard or Rai is
Brassica juncea
Brassica juncea, commonly known as mustard, Indian mustard, Chinese mustard, vegetable mustard is the species of flowering plant belonging to family Brassicaceae. The leaves, seeds, and stems of Brassica juncea are edible. The mustard condiment which is made from the seeds of Brassica juncea is called brown mustard and is spicier than yellow mustard. So, the correct answer is 'Brassica juncea'.