The Verdict: Not eligible
Without a Thai parent or an unbroken Thai line, descent is closed to you. If your spouse is Thai, our marriage quiz covers a much shorter route; otherwise look at skilled migration.
Section 7(1) is Thailand's only descent rule. There is no ancestry visa or heritage route for people of Thai descent outside it.
If you were born in Thailand to non-Thai parents, the 1972 revocation and its reversal may apply to you. That turns on birth and residence in Thailand, not ancestry: see our reacquisition quiz.
For a long stay without a passport, our digital nomad, retirement and golden visa quizzes cover the options.