You can't, since BTC is on Bitcoin network only, and you can't find it on Tron, Ethereum or any other chain, you may find pegged versions but they are not real and doesn't have security of native BTC.
Give up possibility to find BTC elsewhere except on Bitcoin network itself and swap your Tron USDT to native BTC via instant exchanges. Aside from what Xal0lex suggested above, myself use SwapSpace, it's aggregator of instant exchanges.
[1]
https://swapspace.co/