Goan town’s layout is with United States of America (6)

I believe the answer is:

mapusa

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'goan town's' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'layout is with united states of america' is the wordplay.
'layout' becomes 'map' (I can't explain this - if you can you should give a lot more credence to this answer).
'is with' says to put letters next to each other.
'united states of america' becomes 'usa' (synonyms).
'map'+'usa'='MAPUSA'

Can you help me to learn more?

I've seen this clue in The Hindu.

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