Can you add Tron (TRC-20) to MetaMask?
Tron is not an EVM chain, so MetaMask cannot hold TRX or TRC-20 USDT.
Why it does not work
MetaMask only speaks the Ethereum JSON-RPC protocol and only understands addresses starting with 0x. Tron addresses start with T and use a different signature scheme entirely. No RPC setting changes that.
Search results promising a “Tron (TRC-20) RPC for MetaMask” are either describing a bridged wrapper token on an EVM chain, or they are simply wrong. There is no setting to change.
What to use instead
TronLink
The reference Tron wallet, browser extension and mobile.
Trust Wallet
Multi-chain wallet with proper Tron support.
Ledger hardware wallet
Supports Tron through Ledger Live.
If you already sent funds to the wrong address
Funds sent across incompatible networks are generally unrecoverable, because no one holds the key to that address on that chain. The one exception is a deposit to an exchange: exchanges sometimes recover wrong-network deposits for a fee, so open a support ticket with the transaction hash before doing anything else. Anyone who contacts you offering to “recover” it for an upfront payment is running a scam.