Assam Finance minister Himanta Biswa Sarma has said it is impossible for an immigrant to provide proof of religious persecution.

Sarma, who is also convenor of the NDA's regional wing North East Democratic Alliance (NEDA), said that it is not possible for the person to go back to his country of origin and collect a copy of police report to show that he was subjected to religious persecution. Assam has been witnessing protests against the Citizenship (Amendment) Act with the people apprehending that it will hurt their interests.

"It is not possible for an applicant to prove that he had been subjected to religious persecution in his country of origin. Because if he has to prove it, then he has to go to Bangladesh to collect an FIR or police report," Sarma said after a party function on Saturday.

"You cannot prove fear of religious persecution or religious persecution itself. How can you prove it? Somebody will challenge it.

"That is what my assessment is. You will ask a person to go back to Bangladesh and ask him to collect videographic or photographic evidence of religious persecution?" he asked. The Assam government has requested the Centre to include submission of evidence by an applicant that he was in the state prior to 2014 in the rules of the CAA, which are under preparation, the NEDA convenor said.

"Our firm view is that in order to prove that you have come to Assam before 2014, you have to prove it through documents like a bank account opened prior to 2014 or name in the electoral roll prior to 2014 or NRC application before 2014," the BJP leader said.

The Assam government wants a very short window period to establish citizenship under the CAA because rumours are being spread about the possible number of beneficiaries under the Act.

"Our firm view is that the applicants will be in the range of 3 lakh to 5 lakh. These are the people who are staying in Assam from 1972 or 1975.

"We want to end this confusion in Assam. So, we requested for a very short window period because our target people are already selected during the process of NRC.

"Everybody knows that my name is not in NRC, so there is no confusion. No confusion on the applicant's side, no confusion on the government's side. Just go and apply. It will hardly take 2-3 months. Somebody whose name is not in NRC, they can go and apply," the minister said.

The Act aims to provide Indian citizenship to Hindus, Jains, Christians, Sikhs, Buddhists and Parsis entering India on or before December 31, 2014 from Bangladesh, Pakistan and Afghanistan after five years of residence here.

The Supreme Court has issued a notice to the Centre on a batch of 59 petitions challenging the validity of CAA. The next date of hearing is January 22.