The BJP and its allies are likely to retain Assam and gain only the Union Territory of Puducherry -- which is up for the next round of elections along with four key states, show an aggregate of opinion polls was released on Wednesday evening. Elections begin on March 27. Only one opinion poll was conducted in Puducherry, which predicts that the BJP will emerge as the victor with 21 of the 30 assembly seats. Nine will go to the UPA which ruled Puducherry before it came under President's Rule, C-Voter predicted.