Upvote:2
You don't need a single PNR to be able to use the 24 TWOV facility. All you need is to have tickets for flights that arrive and leave within 24 hours. Plenty of direct flights DEL/BOM<->PEK.
Upvote:3
Singapore allows a visa-free transit for nationals of Bangladesh (which is an Assessment Level II country in Singapore's classification). Singapore Airlines offers direct flights from Dhaka to Singapore and Singapore to Beijing.