Lot of information on the sticky thread is outdated and misleading (as rules/situation have changed)

The explanation by satish_ny is correct. May be his post should be made sticky (after adding information about Indigo)

(Have spent 8+ hours over last 2 days researching and calling various airlines)

Regarding original question from OP:

a) If your BOM-BDQ leg is on single ticket (that is issued by Delta then Jet will honor 2 piece internatinal allowance - although untrained ground staff may try to collect extra baggage allowance but with help of ground supervisor you will be able to resolve that issue)

b) Other option is to buy "Special Fare" listed in Jet Airways home page from their US office which will allow 2 bags (As per Jet airways, no one buys them as it is THREE times (USD 185 one-way instead of USD 56 for your sector) more expensive

c) In all other cases, Jet will apply normal domestic allowance which is 20 kg (not 1 bag as pointed by someone here correctly) and per kg fee is very high

d) SpiceJet and GoAir rules are listed by satsh_ny and are correct as of this morning as per respective airline. But none of them fly BOM-BDQ sector.

e) Seems Indigo fly that sector but someone else will have to post the actual authentic details about baggage for Intl connections as I have been unable to get those. (website seem to indicate 20kg allowance, Rs510 for each extra kg - although you can buy 10kg extra for Rs1500 at the time of booking- and it seems no interlining with anyone)

Some alternative that have been suggested:
a) Have a friend fly (preferablly student or healthy senior citizen) with you which will cost less than $40 (make sense if they were going to BDQ any way)

b) Arrange for a car to pick you up and take you to Borivali and get roomy comfortable First Class A/C Train to BDQ central. You avoid hassle of transfer to domestric. Arriving at BDQ downtown is much easier than arriving at BDQ airport for folks coming to recieve you. And most probably you will reach your Vadodara destination sooner.[/QUOTE]