In Christianity, 'Hosanna' is the cry of praise or adoration shouted in recognition of the Messiahship of Jesus on his entry into Jerusalem, Hosanna! Blessed is the one who comes in the name of the Lord! It is used in the same way in Christian praise.
Overall, it seems that "Hosanna" is a cry for salvation; while at the same time is a declaration of praise. Therefore, it may be derived that this plea for help is out of an agreeably positive connotation.
The word comes from Hebrew, and means "Save, now!" In Jewish liturgy, the word is applied specifically to the Hoshana Service, a cycle of prayers from which a selection is sung each morning during Sukkot, the Feast of Booths or Tabernacles.
In Ek Deewana Tha, Hosanna is the title of a song sung by Leon D'Souza and Suzanne D'Mello.