>>546 >>549

ヒンドゥー教のカーストは宗教上は変えられないとされるが、実際に変更できた事例はあるらしく（江戸時代のハードコアな儒教原理主義者とヒンドゥー教原理主義者は反論するだろう）、儒教の士農工商（議論）に類似する点が多くある

儒教の士農工商の枠組みにおいて例外的に裕福で影響力のある町民や百姓が下級武士・郷士になることがあったとしても、競争によらない血統・コネで出世する事例が圧倒的過半数だろう

- 現代の法律上はカーストのアップグレードは可能（ダウングレードは被差別階層の優遇措置があるため不可）
- ブラフミンやクシャトリヤが認めればアップグレード可能

https://www.quora.com/In-India-can-a-person-change-their-caste-If-so-how-does-one-do-this
Parama Devi, Founder and Director at Jagannatha Vallabha Vedic Research Center
Answered Sep 28, 2018 · Author has 2.4k answers and 306.8k answer views
There are 2 aspects of the issue.

One is the legal aspect. Under the present legislation, it is possible to change one’s caste upwards and not downwards because
that would mean cheating for the purpose of obtaining the special privileges (called “reservation”) that the government gives to
the lower castes, specifically SC (scheduled castes), ST (scheduled tribes) and OBC (other backward castes).

So you can simply write an affidavit with some witness and get it certified by a notary, and at the next census you show the affidavit to the questioner.
However, hardly anyone does that because there is no legal benefit in belonging to a “higher caste”, so you do not need a “caste certificate”.

The second aspect is SOCIAL, generally described as “religious” but the definition is not really fitting, because the caste system has NO BASIS in the actual original genuine Hindu society.
The actual original genuine system is called VARNA, not “caste”.

However, ignorant or ill-motivated “religious Hindus” keep confusing the 2 concepts to perpetuate their disastrous BIRTH PREJUDICE,
that all Hindu scriptures condemn as the very root of all ignorance.
Historically, there are innumerable examples of people who “changed their varna” simply through recognition awarded by a single
brahmana/ guru, or by the local assembly of brahmanas, or by the local king.