1. Which airline will be able to allow me travel with twins from Canada to India?
You have to check with each airline. Air Canada requires one adult per infant. Not sure if this applies if you buy seats for both babies. You might want to ask, if you're willing to buy tickets for both of them.
http://www.aircanada.com/en/travelin...ant-child.html
Vague but I think you can on Lufthansa, if one baby has a seat. I included them because this airline serves both the Subcontinent and Canada quite well. Look into other companies too. I've flown LH many times between Frankfurt and California and they're good about accepting foreign car seats. Since you will have to buy a seat for one baby and bring at least one car seat, you need to check into this issue.
I don't recommend any British companies because they don't allow car seats that face backwards. An infant bucket-style seat would be easier for travel and they will refuse it. Also, Heathrow, where I worked for 6 years, is a very grim connection point!
http://www.lufthansa.com/online/port...d=1871017&l=en
You may have better luck with U.S. companies. If they do accept two infants for only one adult, they will require you to purchase a seat for one of the babies. You can't have two infants on your lap.
You might also want to consult twin-specific websites to get other ideas.
2. Do I need car seats in plane? Are they allowed?
Again, it depends on the airline. It depends on what the nationality of your car seats and the airline you'll be flying.
3. Will be given bassinet for babies or it depend on availablility?
You'll only get one bassinet.
4. I have double stroller, is that allowed? Will I be able to use it during stops for connecting flights or I need to buy different single stroller and keep one baby at my sholder in backpack?
Again, it depends on your airline. Most North American companies do return your stroller. Many European airlines wont and you'll have to get it at baggage claim, at your final destination (you'll have to make do on any layovers).
I don't have twins but my children are fairly close in age and I have three. I found it easier to use a good baby carrier and a single stroller but that's very individual. The dynamics with twins are different, I know. I did have a double stroller but never used it for travel.
5. What are the advise from those who alread travelled with baby or babies as this is going to be my first air travel?
Here's my non-commercial article, you might want to check out.
http://flyingwithchildren.blogspot.com
I also came up with about 90 various articles by googling "twins solo air travel".
Last but not least are there an charges for babies, although I am worried more to take them alongwith me than money part
Again, it depends on the airline you take. You will have to buy at least two seats, and I would recommend getting three. Much easier when you're outnumbered by your offspring!
Also, just as a tip, don't be "duped" by child fares. I've paid less without a child fare than I would have on an airline that doesn't offers it. Do the math. Get ALL prices. Don't eliminate any airlines just because they don't have a children's fare.
Another tip; airport taxes are now quite high. Every layover station will nap you for this. Keep connections to a minimum. It's both easier when you're flying alone with multiple children AND it will probably be cheaper too.