According to Richard Attenborough, this film was one of the major reasons why his Gandhi had major problems with the Indian Government for many years.
While the Indian government may have not liked the portrayal, in fact Gandhi does not appear very much in the film at all, and when he does, he is presented in a respectful way. But it is a film which gives equal time to his assassins, and which portrays them somewhat sympathetically. That may have been the real offense.
The movie was banned in India in 1963 due to the sympathetic portrayal of Nathuram Godse and a maligned depiction of his life, even though the disclaimer of the movie in the beginning states that "Nine Hours to Rama" is historical fiction.
J.S. Casshyap, playing Gandhi, was the only actual Indian playing a leading role in this film, where all the most prominent characters are supposed to be Indian. Other leads were played by actors who were German (Horst Buchholz), Puerto Rican (Jose Ferrer), Canadian (Don Borisenko), American (Diane Baker), Welsh (Valerie Gearon) and English (Robert Morley, Harry Andrews). This may be a further reason for the film being so intensely disliked in India, and these casting decisions were much criticized elsewhere, too. The film was a huge box-office flop.
The banning of this film by Indian government caused it to have a very limited run there and it was a big box-office and critical flop elsewhere. Coming after the indifferent box-office performances of "Fanny" and "One, Two, Three", it finished off the ambitions of its leading man, Horst Buchholz, for Hollywood stardom. Following his agent's recommendation, Buchholz returned to Europe to star in an Italian movie with Bette Davis. Director Mark Robson had called him "the hottest young actor in films" during shooting, and, many years later, cast him in a small role in "Avalanche Express", which was Robson's final movie.