Who is Singhji/Gopal Sudha's father from Sister of My Heart and what is their importance?

Singhji turns out to be two characters in one. He is actually Sudha's father, Gopal, who serves the family as a chauffeur. Because his face was burned badly during his fight with Haldar, Gopal's family does not recognize him. In this way Gopal is able to be part of his daughter's life, but still keep from hurting his wife, Nalini, any longer.