He has the Romanceaspiration, and the Cancerzodiac sign. As far as personality, Karan is somewhat neat, active, and nice. But he is quite shy and somewhat serious. According to Karan's SimDNA in SimPE, his hair was black before it turned grey. According to his age data, he had 20 days left in the elderlife stage when he died.
Karan uses the 3rd Maxis face template in Create a Sim, except the eyes and nose which use the 14th face template. Also the jaw is shorter than on the default face. However the jaw is only shorter on teenage, adult and elder males, which may mean that the jaw was genetically passed down, as this oddity generally only occurs on Sims whose facial features were genetically passed down.
Karan's SimDNA in SimPE shows that his recessive alleles are for blond hair and dark blue eyes. Unlike several other married ancestors from Apartment Life who have memories of their spouses, he only has Mystery Sim memories. However Karan still has memories of Ramir's birth, as well as him getting engaged and married. According to Ramir's memories, he died just after Ramir and Ana Patel got engaged.