Thank you, Kaspars for excellent suggestion! I will now consider going straight to BKK from BOM in Singapore Airlines. In Thailand, we want to visit few tourist sites in and around Bangkok and then go to Chiang Mai and Chiang Rai to round up 10 days trip to Thailand. I guess thereafter I should go to Siem Reap in one of the airlines you mentioned. After spending about 5 days in Siem Reap, I am planning to return to Mumbai via Singapore and on the way stop for 4 days in Singapore to see the city. Any suggestions on pro and cons of this probable itinerary are deeply appreciated from you and other FT members. Thank you again for your thoughtful suggestion.