Originally Posted by Calchas

Ah. Stopovers are permitted on I fares issued from USA-India via LHR. So my guess (and it is only a guess): you have an I fare from JFK to BOM and an I fare from BOM to MIA, combined as an open jaw. Separately you have a side trip from LHR-ABZ return on a N fare.

If there was a proper J class on this service (for instance if you were going to CDG) then a J fare would be appropriate. But either your TA or the computer knew that a J fare was not necessary given the restrictions you were happy with on the other sectors.