The song O Priya Priya from Dil is Copied from the song Oh Priya Priya from Geethanjali. The music director for Dil were Anand-Milind. Here is O Priya Priya song from Dil.
And here is the original Oh Priya Priya from Geethanjali directed by Mani Ratnam. The music is by Ilayaraja.