In practice the government will have the last word on what an individual’s rights are, because its police will do what its officials and courts say.
Conclusion
But that does not mean that the government’s view is necessarily the correct view.
Rephrase: The government's view of individual rights may not be correct.
Evidence
In practice, the government will have the last word on what an individual’s rights are because its police will do what its officials and courts say.
Evaluate
Like most Main Conclusion questions, there is an important pivot (But / Yet / However) that comes before the conclusion, and then the conclusion is followed by support.
The argument presents an initial statement about the government's practical authority over defining individual rights, which might lead someone to assume this view is correct. However, the author immediately pivots with "But that does not mean," signaling that the statement following this pivot is the beginning of the author's argument.
We aren't given a keyword to distinguish whether it's saying, "But [conclusion]. After all [evidence]" or saying "But [evidence]. Therefore [conclusion]."
However the sentiment "the government isn't necessarily correct" is the same as "the government may be wrong", which sounds opinionated, and thus like our conclusion.
And the semicolon " ; " after that claim is signaling that we will now hear support for that claim.
Goal
Find the best available meaning match for