To purchase a flat in Kottayam, you’ll need to ensure the property’s title is clear and check for any legal encumbrances. Verify the property’s compliance with local zoning and building regulations. Obtain the original sale deed and other title documents. Ensure that the builder has necessary approvals from local authorities, such as the Kottayam Municipality or Panchayat. Additionally, verify that the flat has a completion certificate and an occupancy certificate. It’s advisable to consult a local lawyer to guide you through the due diligence process and the registration of the property.