What kind of transaction do you have in mind?
If your transaction triggers inference on some AI model as showcased here, the execution can take a few seconds, so your TPS is lower than 1 in this case.
On the other hand, if your transaction needs to do little work, more than 1000 TPS is achievable as previous measurement results have shown.
You asked specifically about a single canister but it is possible to achieve even higher numbers using a multi-canister architecture.