I think i have read some where you cant use a target lock on the turn you get it..

Is that wrong, As i have been playing that you can only use the lock on the following turn.

You can use the target lock the same turn you gain it. Using tokens (target lock, focus, evade, or any future tokens) does not count as an action. In fact, one reason you may choose to wait to use the target lock is that on the next turn you can focus and greatly increase your hit chances.

You might be thinking of R5-K6's ability. Target locks acquired through him cannot be spent this turn.