Welcome to FlyerTalk.

I'm unclear from your post what you are trying to achieve.

Are you asking if it's worth transferring your AMEX point to Avios to book a redemption flight from JFK to DEL ? What cabin are you travelling in ?

What is the other option for you if you don't go down the Avios path ? Do you already have the AA miles ?

You should be aware as countless posts in this forum have explained, redeeming for economy flights with BA is seldom worth it on long haul because you end up saving very little money once taxes/surcharges have been paid.

Also note that LHR has high departure taxes that can be avoided if you merely transit there (transit is defined at less than 24 hours between inbound and outbound flights).

Please post with more details so that more help can be provided.

BAH