The entire process had sparked fears of a witch hunt against the state's ethnic minorities, reports the BBC's Joe Miller.
In an attempt to lower the risk of violence, organisers have been quick to point out that no-one omitted from the final draft will face immediate deportation.
A lengthy appeal process will be available to all - even if it means millions of families will live in limbo until they get a final decision on their legal status.
Around four million Bengalis - a linguistic minority in Assam - have now fallen foul of a long, bureaucratic process known as the National Register of Citizens, or NRC.
The government in Delhi says the register, which has not been updated since 1951, had to be revised, in order to root out hordes of illegal migrants from nearby Bangladesh.
As per the Assam Accord, an agreement signed by then prime minister Rajiv Gandhi in 1985, all those who cannot prove that they came to the north-eastern state before 24 March 1971, will be deleted from electoral rolls, and expelled.
But activists say the NRC is being used as a pretext for a two-pronged attack - by Hindu nationalists and Assamese hardliners - on the state's legitimate Bengali community, a large portion of whom are Muslims.
(Excerpts from bbc.com)