If you are light skinned you are granted an upper caste status. If you are dark skinned but speak good English you get an acceptable 'firangi' (foreigner) caste. Otherwise you are an outcast.

If you are Christian or Muslim with ancestors who converted from Hinduism then under the current government you may apply for reentry using the 'ghaar vapsi' (return home) application form. You can petition for a high caste reconversion in the form but normally you are reconverted to the caste of your ancestors after going through purification rituals and circumambulating the sacred fire.

You’re a foreigner/outsider. You’re not part of the caste system. Brahmins are technically not even permitted to leave India. But if you’re white you would probably be treated very well, just wouldn’t be considered a part of society.