Aniline is an aromatic compound in which group is attached to the benzene ring.
Although the group of Aniline is ortho and para directing in nature whereas in acidic conditions Aniline is meta-directing.
the group is ortho and para directing because of resonance they donate electrons to the Benzene ring and at the same time remove an electron towards themselves due to the +1 effect from the aromatic ring.
In the ortho and para position of resonance structure there present a negative charge.
If the yield of ortho and para products.
But in an acidic medium, Aniline gets protonated and forms an Anilium ion which is meta directing. So, Aniline is meta-directing in acidic conditions.
So, we get three isomers ortho, meta, and para as well but the major one is meta and para.