Karam Dharam Apna Apna is the tale of Gauri, an innocent and charming middle-class Bengali lady. Her father's bosom friend is a Punjabi business tycoon,Mahen Kapoor. Mahen and his wife Nikhila are childless. As a result, his parents and they dote on Gauri. Mahen proposes her marriage with Shashank. On the day of marriage to her utter shock, Gauri finds that she is supposed to marry Shiv, Mahen's arrogant son. She learns that Shashank has refused the match,so the Kapoors have dragged Shiv to save the day as the bridegroom. She can’t accept the turn of events.Sheescapes from the venue. She comes across a stranger, Anupam, who gives her advice to face her problem and not to of run away from it. She comes back to the wedding, much to the annoyance of Shiv, who was expecting that she would not give in.
They get married, but Shiv vows to make her life. Gauri’s warm nature melts his heart and hatred gives way to liking. On her part, she starts unconditionally loving Shiv without any expectation. After the wedlock, a string of accidents happens to her. It comes to light that Shiv's horoscope has a disturbance. For which his first marriage won’t last long due to the wife's death. Knowing this, Nikhila had brought around Shashank to cancel his engagement with Gauri. As a result,Shiv is convinced to stand in as the groom. Shiv loves his childhood sweetheart Ipshita and wants to protect her from the doom of his faulty horoscope. Gauri refuses to leave Shiv even after learning the consequences. Gauri's love makes Shiv feel guilty. The day prophesizedas Gauri's death is near. In the time, as a cover-up, Nikhila persuades Ipshita to agree to marry Anupam, who is an old buddy.
Gaurifaces a major mishap but survives. Ipshita turns insecure.She forces Shiv to divorce Gauri. But, Shiv can not do so, as he has consummated his marriage already and Gauri is expecting. Ipshita gets hitched to Anupam when she accepted that Shiv would not abandonGauri. The story moves forward by five years. Gauri and Shiv are doting parents of twin sons Priam and Om and a beautiful daughter Shanti. Gauri is an obsessed mother who cannot bare enough time for Shiv. He thinks he is happy, but still reminisces his first love. Ipshita is now a renowned writer and has divorced from Anupam. Shiv’s mother Nikhila wants Ipshita back in Shiv's life. Samar, Shiv’s long-lost brother, is found. Nikhilademands Samar to enter the family as Shiv. Nikhila's plan of getting Gauri's signatures on some property related legal documents as Samar achieves the act.
Mahen's sister Maya, Ipshita and Nikhila conspires against Gauri. Ipshita has a one-night stand with Shiv exploiting his emotional vulnerability. Gaurireveals Nikhila's evil plans. The family drives out Nikhila from the house. Maya, Nikhila, and Ipshita with the help of doctors produces a fake report stating Gauri has a brain tumor. She learns about Shiv and Ipshita's night out and that she is pregnant. Preparing for an early death, Gauriconvinces Shiv to get engaged to Ipshita. However, Gauriunderstands that she istrapped and, with Samar's assistance, reveals Ipshita's true colour. Shiv comes to know that Ipshita is acting out her pregnancy and drives her out of his house. After all these, Nikhila changes for better and gains back her place in the family.
Then after that, Mahen'slong detached nephews Asim and Moksh enter the Kapoor mansion, along with Shashank, their business partner. One night, Shiv is cruelly murdered by the trio. After his death, they harass the family. Then, Samar comes across Shiv's ghost. The ghost lets Samar about the murderers. Samar vows to take revenge. Gauri and Samar get Asim and Mokshcharged for Shiv's murder, but Shashank flees. He also stops appearing before them after this. Now, the family start insisting Samar get hitched to Gauri. However, the duo rejects the idea. Now the twist in the tale, Nikhila is murdered.
