India's Ombudsman-type mechanism eventually took the form of the Lokpal at the Union level and the Lokayukta at the state level. Tracing which body first proposed this institutional design, rather than which body merely worked on corruption in general, is the key to answering this question.
The specific proposal to create Lokpal and Lokayukta institutions on the Ombudsman model was first made by the 1966 Administrative Reforms Commission, well before the later committee, movement, and second commission engaged with the same idea.
Hence, the correct answer is Administrative Reforms Commission, 1966.