Getting a loan in Thailand with only a tourist visa is problematic, if not unrealistic. For this, you need to provide a banking history and an authorization to work in Thailand. On average, the annual percentage for a Thai loan is 8%.
You can take out a loan or you can agree on payment in installments with the seller. Most often, the customer is given the possibility of paying in installments for a period of 1-2 years. In rare cases it can be extended to 5 years. When buying a home in the secondary market, payment by installments is not possible.