"Shou Lung: Imperial China
T'u Lung: Historical dissident states based in South China during eras of political disunity (i.e. Nanzhao and Kingdom of Dali, formerly centred in present-day Yunnan province)
Wa: Feudal Japan (Edo period)
Kozakura: Japan[5]/Ryukyu Islands (Ashikaga period)
Northern Wastes: Historical non-Sinic tribal societies of Manchuria or Northeast China
Tabot: Tibet
Koryo: Korea
The Island Kingdoms: Pre-colonial Hindu-influenced civilizations of Indonesia and the Philippines.
The Plain of Horses: Historical Mongolia. This region is the Kara-Tur portion of the Hordelands, also known as the Endless Wastes.
The Jungle Lands of Malatra: Pre-colonial civilizations of Indochina (historical versions of the Khmer Empire and Vietnam) as well as the hill tribes inspired by their real-life Southeast Asian counterparts."
From Wikipedia.
Also Wa and Shou Lung have Spelljammers.
The main religions of Kara Tur are The Way, The Path of Enlightenment, 8 Million Gods, Lords of Creation (old Vedic Hinduism, but with a female Indra), Elemental Tribes (worship Elemental Deities and some Hindu Gods), am I forgetting any?
There are some worship of Faerun deities, but it's rare and in some places prosectuted.
Also Tu Lung and Mulhorand have diplomatic ties that go back at least a century, so make of that what you will.
There was supposed to be a fantasy version of Thighland and/or Sri Lanka, but they never got to it.
Oh and there is one secret Spelljammer port.