I would avoid 1 (DFW - EWR - BOM - MAA - Air India ) in your list as EWR-BOM has a stop over in FRA.
My preference is minimum connections so LH would be my first preference and also stop over in Europe is better because both legs of the flights are evenly spaced out. My preference will be
1. DFW-FRA-MAA (LH)
2. DFW-EWR-BRU-MAA (9W)
3. DFW-JFK-BOM-MAA (AI) with JFK-BOM direct flight in a 77L and also the wait time in BOM is very less.
4. DFW-IAH-DOH-MAA (Qatar)
5. DFW-IAH-DXB-MAA (Emirates)
Options 3-5 one of the segments is ultra long (14 - 17 hours).