SQ one way-- Y+ / C India- USA $660/$1550
 

Found one-way fares on Singapore Air that are very good, especially as one way tickets.
Premium Economy:
BOM-SIN-LAX/SFO/JFK are all around INR 46,500 one way. Be careful that sometimes these are priced with regular Y on the India-SIN segment, then Y+ on SIN-USA.
R Class. You can route on the nonstop SIN-SFO/LAX-EWR, or do the one-stop via NRT/HKG/FRA to the USA.

Business Class:
Ahmedabad is actually INR92,000, while BOM/DEL (and I assume others) are around INR 115,000 (US$1575) one way.
D Class. Seems that you can route on the nonstop SIN-SFO/LAX-EWR, or do the one-stop via NRT/HKG/FRA to the USA, depending on the specific Origin and Destination.

Largely discussed in this thread: $1,300 One Way (Biz) India-EWR (SIA Longest Flight)

Are you seeing the US$ 1,575 fare on the SIN-EWR non-stop when originating from DEL/BOM? If so, what dates?

No but I do see BOM-JFK (via SIN/FRA) for US$742 one way over the holidays. Saw it for a bit less last week as well.
Ended up booking BOM-SIN-NRT-LAX for US$660 one way in Y+, might consider changing it to Business Class later if that can be done as a "change fee"

You mentioned biz class at US$1575 (D class). Are you able to share sample dates for BOM/DEL-EWR/JFK?

No. Sorry I only see Business Class to the West Coast.
The Y+ is available to both West Coast and East Coast.

ok thanks.

Can you please share an example for a routing through FRA? Tried to replicate in both J and Y+ but price about USD 500 without any stopovers.

NO J to East Coast.
12/30 and 12/31 :
Y+ BOM-SIN-FRA-JFK was around INR52000 last week.

Saw One way AMD EWR for $ 1275 Jan 9. J.

Anyone can find a better deal (ex BOM is fine), final destination will be ORD Can take via SIN FRA JFK also.

Thanks