These days, this particular verse is very popular among Hindu apologists (and their parrots). And it's quoted out of context (obviously), which makes it's extremely misleading. It's funny to see Hindu apologists resenting Muslims and ironically using the same techniques as Muslim apologists (deception, changing the meaning of verse, quoting it out of context). Anyways, let's get to the topic.
Manu 10.65
The Shudra attains the position of the Brahmin and the Brahmin sinks to the position of the Shudra. The same should be understood to be the case with the offspring of the Kshatriya or of the Vaishya.
The immediate previous verse, Manu Smriti 10.64 says the following -
Manu 10.64
If the child born from a Shudra woman to a Brahmin goes on being wedded to a superior person — the inferior attains the superior caste, within the seventh generation.
Explanation: If the daughter of a Shudra female from a Brahmin and all their female descendants marry Brahmins, the offspring of the sixth female descendant of the original couple will become a Brahmin. Simarly, the children of Brahmin females will become Shudra if they marry Shudra males and keep repeating the procedure for 7 generations.
Conclusion: You, the Shudra can never become a Brahmin yourself. But you can console yourself with the fact that your maternal great grandchildren could (If your daughter, her daugher and subsequent daughters in the lineage upto 7th generation, all agree to sign up for the pain, that is).
You would be dead anyways. You could enjoy the show from the heaven (or hell, since it is more likely for sinful Shudras) though. I leave it to your wisdom to decide how practical this scheme is and whether you want your daughters to sign up for it.
And if you belong to a Varnasankar Jati (Mixed Caste) like Kayastha, Yadav, Kurmi etc., you shouldn't even bother. Go home and sleep.
