The victim has been identified as Ashok Kumar Rakyam, who also runs a Trust where he distributes books to poor students.
"The incident took place at around 1:30 PM when Ashok was at his residence. His father and domestic help Bablu were also present. His office is in the basement of the house. Around 1:30 PM, two men entered his house asking for a form regarding the Trust to distribute books," said a police official.
They first overpowered Bablu and snatched keys from him. They then took control of Rakyam and his father and then the three of them were locked inside the room, he said.
The robbers have decamped with Rs 20 lakh cash and jewellery worth Rs 25 lakh. A case of robbery has been registered at CR park police station and sketches of the first two who entered the house are being prepared, police said.