The 19-year-old won the accolade ahead of Argentina's Maico Casella and Blake Govers of Australia, who finished second and third respectively.
Kumkum, who featured in some of the most memorable songs in Hindi cinema, passed away on Tuesday. She was 86.
Sagar's son had said that the last rites of his father would not be performed until the chief minister arrives at their hometown in Deoria.
Mani Ratnam is experimenting with a real-life historical in Ponniyin Selvan, points out N Sathiya Moorthy.