First of all, I strongly support all of you to take actions to claim your rights in the immigration process. Everyone deserves a procedural and substantive equal protection under the Constitution law.
However, as a practice attorney (not doing immigration), as far as I understand, it is very hard to challenge the government's actions in this regard, because the lowest scrutiny standard (so called "rationality" review) will apply to justify the governmental actions in reallocating the unused visa numbers to Indians rather than Chinese. Any reasonable justification will fulfill the purpose.
Again not intend to discourage, just provide some information.