Legal Eagle #3

 This committee possessed the concerns for unity, diversity, socio-economic representation, and above all, the concern to reduce turmoil.

It is often believed that X, a key member of the committee, spearheaded the committee's success due to his efficient lobbying of certain "autonomous" states, then called in the Imperial Rule as Y.

Which ad hoc committee, whose resultant was a hand written copy by Prem Behari Narain Raizada, and is the largest of its kind?