If you mean the blockchain nodes themselves, then nodes will not display this data. This is really a market question, not a question that the blockchain protocol itself should answer. Every market has their own answer to what the price of TON is, and arbitrage will slowly balance it out.
There are services that aggregate many markets' prices together to get a simple answer for you, though. tonapi.io does allow for this:
CoinMarketCap and CoinGecko both provide their own APIs as well.