It would seem reasonable to place an intake limit of 10% from any one country, and limiting males to a maximum of 49%.
Right now, lets be honest, the H1B is giant immigration scheme for Indian males to get into the USA: 75% of applicants are Indian, and roughly 70% of applicants are male.
https://tech.economictimes.indiatimes.com/news/people/three-...
https://www.computerworld.com/article/3050365/how-many-h-1b-...
With these kind of diversity requirements, it would also be much harder for crooked companies like Infosys to racially discriminate against non-Indians:
https://economictimes.indiatimes.com/tech/ites/infosys-faces...
The green card lottery visa has diversity metrics built into it explicitly, which is probably why it receives minimal negative attention.
India holds 17% of the world's population. Any program that is designed for diversity would have a 15-20% Indian population. That is much smaller than the current number, and in fact it would be a fairly different set of Indians: victims of sexism, casteism, "colorism", etc.
This could work out pretty well. Indian social inequalities would be reduced, US tech companies would get an infusion of extremely diverse workers on strong career tracks. If you believe that diversity is good for the workforce, this would be a huge boost.
But the straight/cis/brahmin/male Indians would get mad.