"It was unfortunate that the Opposition members did not turn up for the consultative meeting on RIIN in Kohima last month," Rio told the Assembly while informing it about the government's stand on the issue.
However, he said that every tribal hohos, NGOs and civil society organisations (CSOs) were present in the meeting and extended their support to the exercise.
RIIN is aimed at preparing a master list of all indigenous people and checking the issuance of fake indigenous inhabitant certificates.
Rio said that in the consultative meeting, all the tribal hohos, NGOs and CSOs endorsed the decision of the government and extended their support on the exercise of RIIN.
"However, they also cautioned that proper modalities should be worked out based on customary laws and practices practiced by their own respective tribes," the Chief Minister said.
He sought opinions and constructive criticisms from all sections of the people, including the legislators, on the issue.
The Chief Minister said that a three-member committee has been set up on the issue and its members will thoroughly examine the matter and give recommendations/reports to the government.
He assured that the commission will go into the details and make sure that corrective measures over earlier notifications are taken.
A leader of the Opposition, T.R. Zeliang, said that listing indigenous inhabitants in RIIN should be deliberated at length before implementation.
"Creation of RIIN with 1963 as the basis of categorisation without indigenous Naga being well defined would only victimise certain sections of people," he said.
Suggesting bifurcation of RIIN with the Inner Line Permit (ILP), Zeliang reiterated that proper modalities should be worked out without any hue and cry.
He further urged the government to implement ILP in Dimapur district with the same stringent action as in other districts, saying that it is only to identify non-tribals and non-Nagas.
( With inputs from IANS )