The accused duo has been identified as Shoaib Khandawalla (Ahmedabad) and Nasir Shaikh from Kalyan, Assistant Police Inspector N R Desle of Bazarpeth Police station (Kalyan division) said.
The case was registered based on a complaint lodged by one of the victims.
"The duo duped 51 tourists. Between January and April this year, the accused had collected Rs 19.60 lakh from the pilgrims residing in Thane, Mumbai and Kalyan. The operators issued travel tickets to them, but kept changing the tour dates and never took people on the tour, police said.
However, the duo did not refund the balance sum of Rs 17.60 lakh, which they utilised for their benefits, the police complaint said.
The duo has been charged under sections various sections of the Indian Penal Code.
No arrest has been made in this connection yet, police said.