Movie abstract from IMDB: Three brothers are separated and united after many years - one is brought up a Hindu, another a Muslim and the last (and most memorable) a Christian. Hilarity and adventure ensues.
Movie - Amar Akbar Anthony;
From YouTube: Amar Akbar Anthony is a 1977 Bollywood lost and found action comedy film about three brothers separated during their childhood who grew up in three homes, adopting three religions. They meet in their youth to fight a common villain. It was the biggest blockbuster of 1977, and won several awards at 25th Filmfare Awards including Best Actor, Best Music Director and Best Editing.
The film was directed by Manmohan Desai and starred three actors: Amitabh Bachchan (as Anthony Gonsalves), Vinod Khanna (as Amar Khanna) and Rishi Kapoor (as Akbar Allahabadi). Each of the heroes had an affiliation with a heroine; these women were played by Parveen Babi, Shabana Azmi and Neetu Singh. Nirupa Roy, Pran and Jeevan played supporting roles. The music was composed by Laxmikant-Pyarelal. Kishore Kumar sang for Amitabh Bachchan, and Mohammed Rafi sang for Rishi Kapoor. The soundtrack was one of Mukesh's last soundtracks with Laxmikant-Pyarelal. Anand Bakshi was the lyricist. This movie proved to be a golden jubilee at the box office.