Thank you all for your responses, and the link for the BOM thread. I'm dealing with a lot of moving parts, so cities in India aren't fully decided yet, other than the return will be from HYD.

To explain my issue: As a *G, I will have a baggage allowance on TK of 3 x 23kg which I will fully need on my return, AND I need to get to ORF (3-hour solo nighttime drive from IAD after arrival would simply not be safe, and I must get back that night), so my TK return flight must originate in BOM to keep to 3 segments. Hence the question regarding baggage through-check since I'll need a separate HYD-BOM ticket.

On an AI domestic HYD-BOM ticket, I would get a 45 kg baggage allowance (25 + 20 more for *G), so I'm looking at a possible worst case 24kg excess baggage, which would come to INR 12,000 (500 per kg), assuming that excess baggage is based only on weight, and having 3 pieces is immaterial. A J ticket wouldn't be cost-effective, since it would only get me an extra 10 kg allowance for a INR10,000 price differential.

Sounds like I should plan on paying 12000 excess baggage and expecting to reclaim and recheck in BOM, and any through-checking or higher bag allowance would be based on goodwill, luck, or karma. I just hope TK checkin would be open soon after my arrival into BOM so I can check in and get to the lounge for the 6-hour transit time.

I don't know if my outbound will be to BOM, AMD, HYD, or JGA. Things were looking good for doing IAD-IST-BOM-JGA on a single ticket, but suddenly yesterday the price jumped from USD 1000 to 4000 by adding the JGA segment (it's a glitch since I can buy a separate BOM-JGA ticket for under INR8000 but don't know if it'll be fixed before I have to buy my ticket in the next day or so).