If you do not have a fixed place of business in India, you must register as a Non-Resident Taxable Person (NRTP) by submitting Form GST REG-09 at least five days before business starts. You will need to appoint an Indian resident as your authorized signatory and pay an advance deposit covering your estimated tax liability. Because real estate transactions involve significant tax implications (such as TDS and capital gains), please consult a CA to manage your filings, documentation, and repatriation of funds.