Literally, “not that”.
не то • (ne to)
- the wrong thing, the wrong one, something wrong
- Он сказа́л не то. ― On skazál ne to. ― He said the wrong thing.
- Что-то не то. ― Što-to ne to. ― Something's wrong.
- Used other than figuratively or idiomatically: see не (ne), то (to).