Don’t be mistaken–being disqualified from standing for election is a restriction on his right to free political speech. However, this is a permissible restriction on free speech because the constitution (Amendment XIV) deems that those who engaged in insurrection should not be able to serve in office.
Trump’s argument is similar to arguing that slavery is legal because it says so in the original constitution…disregarding the fact that a future amendment changed that.
That’s because even a grey market Windows key costs US$20 nowadays and that’s over ₹1,600. For comparison purposes, the largest Indian banknote is ₹500.