A hard lump appeared near the tip of my nose after Rhinoplasty. Is it cartilage/callous formation? How can it be removed?(photo)

It is hard to know what that is without examining your nose and seeing the operative report.  However, if I had to guess, I would say that that is the end of the cartilage that comes from your tip out over the nostrils, called the lower lateral cartilage.  I bet you had a "closed" surgery where this cartilage was trimmed.  you have upwardly pointing tip cartilages (cephalically malpositioned) that probably deformed after they were trimmed.  Your tip cartilage is very convex.  If the cartilage is trimmed, it sometimes deforms due to changes in the internal stresses of the cartilage.  To fix this, you would need another surgery to flatten and strengthen this cartilage.  That assumes that what I'm guessing is correct, of course.  I am nearly positive that it will not improve by itself.  It is certainly not swelling at 5 years postop.  Good luck!

Residual cartilage of the lower lateral alar area. Best to seek IN PERSON opinions. ONLY surgery can improve... 

It appears to be prominence of cartilage in the tip.  It would require revision to remove and reshape the cartilage to give a nicer appearing tip.  It is not a difficult operation.  In person examination would help ensure that it really is cartilage.