Question: What  prominent Indian dance choreographer in Hindi cinema provided assistance for the 1963 Indian social film directed by Nitin Bose?

Context paragraphs:
Milan (1946 film): Milan (Union) is a 1946 Hindi social drama film directed by Nitin Bose.  The film starred Dilip Kumar, Mira Misra, Ranjana, Pahari Sanyal and Moni Chatterjee.  It was an adaptation of Rabindranath Tagore's Bengali story "Noukadubi" (The Wreck).  The screenplay adaptation was done by Sajanikanta Das with dialogues translated into Hindi by Pyare Lal Santoshi.  The film's music was composed by Anil Biswas and the lyrics written by Pyare Lal Santoshi and Arzu Lakhnavi.

Dushman (1939 film): Dushman is a 1939 Hindi social romantic drama film.  It was directed by Nitin Bose for New Theatres Calcutta Production.  The film starred K. L. Saigal, Leela Desai, Najmul Hassan, Prithviraj Kapoor, Nemo and Jagdish Sethi.  The music was composed by Pankaj Mullick and the lyrics were written by Arzu Lucknavi.  Nitin Bose besides directing also wrote the story and wielded the camera for the film.  The dialogue writer was Sudarshan.  The story subject about tuberculosis was suggested as a propaganda film by Viceroy Lord Linlithgow and his wife, who were then the Chairman and Patron of King George’s Tuberculosis Fund.

Dharti Mata (film): Dharti Mata is a 1938 Hindi social film directed by Nitin Bose.  The film was also made and in Bengali as "Desher Mati" in the same year by New Theatres.  It starred K.L. Saigal, Uma Shashi, Jagdish Sethi, Kamlesh Kumari, and K. C. Dey.  The music was by Pankaj Mullick and lyricist and dialogue writer was Pandit Sudarshan.  The story, screenplay and cinematography was by Nitin Bose.  The story is about two friends Ashok and Ajay, one interested in agriculture and the other in technology.  Ashok goes to the village to help the farmers while Ajay goes to UK for higher studies in engineering.  The film highlights the need of technology and new concepts for effective farming.

Chandidas (film): Chandidas is a 1934 Hindi social drama film directed by Nitin Bose.  The film was produced by New Theatres Calcutta and was their first big success.  It was remake of the 1932 Bengali film of the same name directed by Debaki Bose.  This 1934 Hindi version starred K. L. Saigal, Uma Sashi, Pahari Sanyal, Nawab and H. Siddiqui.  The music direction was by R. C. Boral with the lyrics written by Agha Hashar Kashmiri.  The credit roll of the film states that the film is "Based on the life problems of the poet Chandidas –A problem India has not been able to solve", which involved the caste schism in India.  The story revolves around the 15th century poet-saint Chandidas who acts out against the deep-rooted bigotry against caste, untouchoubility and the hypocrisy of society, and a washer woman with whom he falls in love.

Dhoop Chhaon: Dhoop Chhaon is a 1935 Hindi movie directed by Nitin Bose.  It was a remake of the Bengali film Bhagya Chakra.  "Dhoop Chhaon" was the first Hindi film to use playback singing.  It was Bose who came up with the idea of playback singing.  He discussed with music director Raichand Boral and Bose's brother Mukul Bose, who was the sound recordist in New Theatres, implemented the idea.

Nartaki (film): Nartakee (Dancer) is a 1963 Indian social film directed by Nitin Bose.  The story and screenplay were by Dhruv Chatterji, with dialogues by S. K. Prabhakar.  Produced by Mukund Trivedi for Film Bharti, its director of photography was Nana Ponkshe.  Director Bimal Roy did the editing for the film.  Choreography was by Sohanlal, assisted by choreographer Saroj.  The music director was Ravi and the lyricist was Shakeel Badayuni.  The film starred Sunil Dutt and Nanda in key roles with Om Prakash, Agha, Zeb Rehman, Pritibala and Aruna Irani.

Chirakumar Sabha: Chirakumar Sabha (A Conference of Bachelors) is a 1932 Indian Bengali film directed by Premankur Atorthy.  The cinematographer was Nitin Bose.  The film starred Durgadas Bannerjee, Molina Devi, Tinkari Chakraborty, Phani Burma, Indu Mukherjee and Amar Mullick.  The music of the film was composed by R. C. Boral who used Tagore’s songs as lyrics.  It was one of the first of Rabindranath Tagore’s works to be made into a film.  The film was remade in 1956 by Debaki Bose.  The story revolves around a group of hardened bachelors who meet on a regular basis, and eventually settle for marriage.

Deedar (1951 film): Deedar (Hindi: दीदार , "glance") is a 1951 Bollywood Hindi language film directed by Nitin Bose and starring Ashok Kumar, Dilip Kumar, Nargis and Nimmi.  A story of unfulfilled love, when hero's childhood love is separated from him due to class inequalities.  It is one of noted tragedies made in early Hindi cinema.  It became a popular film of the Golden era and further established Dilip Kumar as "King of Tragedy".

Rajrani Meera: Rajrani Meera (Rajrani Mira) is a 1933 Hindi devotional film.  It was directed by Debaki Bose for New Theatres Ltd.  Calcutta.  The cinematographer was Nitin Bose with music composed by R. C. Boral.  The film was a bilingual, made in Bengali as Meerabai (1933) and directed by Hiren Bose and Basanta Chatterjee.  The film starred Durga Khote, Prithviraj Kapoor, K. L. Saigal, Pahadi Sanyal, Molina Devi and Indubala.  K. L. Saigal had a small part that of a devotee in the film with Prithviraj Kapoor playing the male protagonist role.  The film made Prithviraj Kapoor who played the role of the King of Mewar, Mirabai’s husband, a big star and is cited as one of his career-best films.

Saroj Khan: Nirmala Kishanchand Sadhu Singh Nagpal, popularly known as Saroj Khan (born 22 November 1948), is one of the most prominent Indian dance choreographers in Hindi cinema.  She choreographed more than 2000 songs .  Saroj Khan was born to Kishanchand Sadhu Singh and Noni Sadhu Singh.  She is married.

Supporting paragraphs: Nartaki (film) Saroj Khan
Answer: Saroj Khan