Within North America , as you are in the Continent of Commencement, the 6 sector rule does not apply. Note too that within North America, a transit is anything less than 4 hours as opposed to international's 24 hour rule.
If you can, avoid London, the airport taxes alone for going through London more than a few times will set you back at least $100 or so!
For the 'Indian' part - you may want to try: HKG-SIN-BOM (on QF) - HKG-SEL-HKG-NRT-DFW-ORD-YYZ.
Note too that even you decide to go land from PRG to ZRH, ZRH will also be counted as a stopover! Hence you may have already exceeded your number of stops within Europe. Be careful on that.
[This message has been edited by Guy Betsy (edited 03-25-2001).]