The Delhi University plans to invite either President Ram Nath Kovind or Prime Minister Narendra Modi for unveiling its commemorative stamp and coin as part of its year-long centenary celebrations beginning May 1, sources said on Sunday. "Since it will be the celebrations of a huge milestone, there are plans to have either the President or the Prime Minister to unveil the commemorative stamp and coin. The President is the Visitor to the university," one of the sources said.