Here is a simple overview of kshetras in Jain cosmology:

• Bharat Kshetra: The central land where humans live and where Tirthankaras are born and preach. It is the main present-world region in Jambudvipa.
• Airavat (Airaavat) Kshetra: A mirrored region opposite Bharat Kshetra; believed to have similar spiritual significance.
• Mahavideha Kshetra: A central region where Tirthankaras are continuously present; considered highly holy in the current cycle.
• Haimavat (Haimavat) Kshetra: Smaller regions between the above, less associated with birthplaces of Tirthankaras.

These four Kshetras describe the major geographic-spiritual divisions in Jain cosmology. You can read more here