In the meantime Jaipal was taken away from the embrace of Muslim League when he was elected to the Constituent Assembly, at Delhi. There he came into contact with the top-rung of Indian leadership which opened his eyes and stemmed his turbulence.
The speeches of Nehru and Patel, Ambedkar etc. made Jaipal as embodiment of national tribal aspiration.
Sardar Patel declared to the Constituent Assembly that:-
“I would like to make one thing clear – is it the intention of people who defend the cause of the tribals to keep the tribals permanently in their present state? I do not think it is in their present state? I do not think it is in their interest to do so. I think it would be our endeavor to bring the tribal people to the level of Mr. Jaipal Singh.”
Jaipal was made the member of Excluded and Partially Excluded Area (other than Assam) Sub-committee along with A.V. Thakkar as Chairman, D.N. Samanta, P.B. Sah, Jagjivan Ram, P.C. Ghose, and R.K. Bose as members. The Committee provided the Constituent Assembly with a principle that the new democratic state had a responsibility for the welfare of tribal people and development of tribal areas and thus tribal problem at once became an integral part of the development of Indian people as the whole.
The Tribals were recognized as Minority, V& VI Schedules to the Constitution were added, various safeguards;protective discriminatory articles in the Constitution were added to give regional bias in place of ethnicity; boosted the morale of Adivasi Mahasabha renamed as Jharkhand Party.
Jaipal invited Pt. Jawahar Lal Nehru, Vijya Laxmi Pandit and Mr Jagjivan Ram to attend the Adivasi Mahasabha to be held in April, 1947.
In March 1947, Adivasi Kisan Samaj was founded by Satish Chand Korha and Mukund Ram Tanti at Chaibasa mostly to fight the government paddy procurement, Adivasi Labour Federation with Brijmohan Bari in March 1947.
In his presidential speech in the Annual Conference of Adivasi Mahasabha held at Ranchi on 13th April 1947; Jaipal was reported to have said that although Muslim League was supporting the Jharkhand separation movement. Adivasi will not allow them to be misled by the League as he was not in favour of Pakistan and did not like to boycott the Constituent Assembly but he however reiterated his demand of separation of Chotanagpur (Jharkhand).
On 18th March, 1947 Mr. Amin Ahmed ICS (retired) and M.L.A. of Chaibasa organized a meeting of Muslim Leagues at Ranchi under the Saida Akhtar Khatun of Banglore and resolved that in future all efforts of inter-marriage between Adivasi and Muslim should be made and large-scale conversion of Adivasi to Islam should be launched by the National Guard so that Chotanagpur was brought under Pakistan, they expected to get 43% population in event of separation and suggested to hold a Chotanagpur Conference at Jamshedpur with Md. Ali Jinnah as Speaker.