Mr. Romeo(1973)

When Pal's son kills a police constable, his best friend, Saxena, the only witness to this murder, comes forward and as a result Pal's son is arrested and charged with murder. Pal pleads with Saxena to change his witness statement, but Saxena refuses to do so, and as a result Pal's son gets convicted and is sentenced to death. Pal swears to avenge his son's death. Years later, Saxena's sons, Ramesh and Suresh, have grown up. While Suresh, the younger son, is serious, studious, and business-minded, Ramesh is quite the opposite. Pal's son, Prem, befriends Suresh and gets him hooked-up with a gorgeous looking girl, and drugs his drinks, thus making him an addict. He falls in love with this girl and wants to get married to her. His parents and Ramesh are opposed to this, and Ramesh goes to the extent of threatening to kill her.