Main Intequam Loonga

Main Intaquam Loonga (English I will take revenge) is a 1982 Bollywood sports film starring Dharmendra, Reena Roy, Amrish Puri and Nirupa Roy. Dharmendra plays a boxer in the film. Footage from this film was used in the 2007 film "Apne", also starring Dharmendra as a retired boxer. It is a remake of the 1978 Kannada film "Thayige Thakka Maga", starring Dr. Rajkumar and Padmapriya.
Dharmendra's son Sunny Deol was used as a stand-in for his father where he is shown doing one hand push-ups at the very beginning of the title song. This was before he made his debut as a leading actor in "Betaab" (1983).
Plot.
Kumar (Dharmendra) is interested in boxing, but his mother Janki (Nirupa Roy) wouldn't like him to be a boxer. He falls in love with his neighbour, Mala (Reena Roy) detective by profession. They are soon to be married. The story moves forward by Mala finding out that G.D. (Amrish Puri), who runs a gym where he trains boxers and only wants his trainee to win the boxing championship, he commits many crimes and she seeks evidence, so he can be jailed.
The story takes a turn when Janki gets a call from mental hospital that Ganga has completely recovered and can be discharged from the hospital. She shares her agony with her husband and tells him that it would be impossible to give back her son to his biological mother Ganga. Overhearing this conversation, Kumar is shattered. But when Ganga meets his son for the first time, she doesn't reveal the truth to him herself, realising that Janki is a heart patient and would die without Kumar and soon moves to Haridwar. Kumar goes to Haridwar to find her and brings her back and gives her a house to stay. He doesn't reveal to Janki about their association. Soon he comes to know that his biological father, Ajay (Dara Singh) was a boxing champion and was killed by G.D.
Kumar decides to take revenge by winning boxing championship against those killers and he finally succeeds. But, seeing the murder of her husband's murderers, Ganga again loses her mental balance and dies on the spot. Kumar comes back home and break the news in front his parents that Ganga is dead, but still doesn't confess that he knows the truth. The story ends with the family remembering Ganga.